The document discusses the history and development of organic light-emitting diodes (OLEDs). It describes how OLEDs operate based on the principle of electroluminescence in organic materials. A basic OLED consists of an emissive organic layer sandwiched between a cathode and anode. When a current is applied, electrons and holes are injected from the electrodes and recombine in the organic layer, emitting light. Improved OLED designs use multiple organic layers to better transport charges and confine recombination.
Snehasis Mondal wrote a report on organic light emitting diode (OLED) technology for his degree in electronics and communication engineering. The report discusses the history and components of OLEDs. It explains that OLEDs are made of organic compounds sandwiched between two electrodes that emit light when voltage is applied. The report also covers the advantages of OLEDs like being lightweight, flexible, and having lower power consumption compared to other displays. It discusses potential applications of OLED technology in various industries.
OLED technology uses organic light emitting diodes to create brighter, thinner, and more flexible displays. An OLED is composed of thin films of organic molecules that emit light when electricity is applied. The first OLED was developed in 1987, and since then OLEDs have been used in various displays. OLEDs offer advantages over LCDs like higher contrast, better viewing angles, and less power consumption. Major applications of OLEDs include televisions, smartphones, and laptops.
This document provides an overview of organic light-emitting diodes (OLEDs). It discusses the history and development of OLED technology. The key aspects covered include:
- How OLEDs work by emitting light when electric current passes through organic material layers between electrodes.
- The basic architecture of OLED displays including organic layers and electrodes.
- Comparisons of OLEDs with LCD, LED, and TFT displays in terms of image quality, power consumption, thickness, and manufacturing costs.
- Advantages of OLEDs such as high contrast, wide viewing angles, and potential for lower costs.
The document discusses OLED display systems. It provides a brief history of OLED development from early observations of electroluminescence in organic materials in the 1950s to modern OLED technologies. It then covers key topics such as the working principle of OLEDs, common materials used like small molecules and polymers, advantages over LCD displays like higher brightness and thinner profiles, and applications of OLED displays.
Organic LEDs (OLEDs) are a type of thin, lightweight LED that uses organic compounds that emit light in response to an electric current. OLEDs can be used for displays and solid state lighting applications. They have advantages over LCDs like being thinner, lighter, achieving higher contrast, and not requiring backlighting. OLEDs operate by using organic material layers, including an emissive layer, between an anode and cathode. When an electron and hole pair recombine in the emissive layer, a photon is released, emitting light. Research is focused on improving the lifetime of blue organic films and reducing production costs.
OLEDs rely on organic materials that emit light when electric current is applied. They have advantages over LCDs like being thinner, requiring no backlight, and enabling flexible displays. However, their organic materials have limited lifetimes and can be damaged by water, so improved sealing processes are important. Product demonstrations include an 11-inch 0.3mm thick 960x540 pixel display and a 3mm thin 11-inch 940x540 display with high contrast ratio from Sony.
OLED (Organic Light Emitting Diode) is an emerging display technology that uses electroluminescence from organic compounds to emit light. OLEDs offer brighter, thinner, and more flexible displays compared to traditional LCD screens. They consist of a series of thin organic layers sandwiched between an anode and cathode, which emit light when electric current is applied. While offering benefits like high contrast and low power consumption, OLEDs currently have drawbacks such as higher costs and limited lifespan.
Snehasis Mondal wrote a report on organic light emitting diode (OLED) technology for his degree in electronics and communication engineering. The report discusses the history and components of OLEDs. It explains that OLEDs are made of organic compounds sandwiched between two electrodes that emit light when voltage is applied. The report also covers the advantages of OLEDs like being lightweight, flexible, and having lower power consumption compared to other displays. It discusses potential applications of OLED technology in various industries.
OLED technology uses organic light emitting diodes to create brighter, thinner, and more flexible displays. An OLED is composed of thin films of organic molecules that emit light when electricity is applied. The first OLED was developed in 1987, and since then OLEDs have been used in various displays. OLEDs offer advantages over LCDs like higher contrast, better viewing angles, and less power consumption. Major applications of OLEDs include televisions, smartphones, and laptops.
This document provides an overview of organic light-emitting diodes (OLEDs). It discusses the history and development of OLED technology. The key aspects covered include:
- How OLEDs work by emitting light when electric current passes through organic material layers between electrodes.
- The basic architecture of OLED displays including organic layers and electrodes.
- Comparisons of OLEDs with LCD, LED, and TFT displays in terms of image quality, power consumption, thickness, and manufacturing costs.
- Advantages of OLEDs such as high contrast, wide viewing angles, and potential for lower costs.
The document discusses OLED display systems. It provides a brief history of OLED development from early observations of electroluminescence in organic materials in the 1950s to modern OLED technologies. It then covers key topics such as the working principle of OLEDs, common materials used like small molecules and polymers, advantages over LCD displays like higher brightness and thinner profiles, and applications of OLED displays.
Organic LEDs (OLEDs) are a type of thin, lightweight LED that uses organic compounds that emit light in response to an electric current. OLEDs can be used for displays and solid state lighting applications. They have advantages over LCDs like being thinner, lighter, achieving higher contrast, and not requiring backlighting. OLEDs operate by using organic material layers, including an emissive layer, between an anode and cathode. When an electron and hole pair recombine in the emissive layer, a photon is released, emitting light. Research is focused on improving the lifetime of blue organic films and reducing production costs.
OLEDs rely on organic materials that emit light when electric current is applied. They have advantages over LCDs like being thinner, requiring no backlight, and enabling flexible displays. However, their organic materials have limited lifetimes and can be damaged by water, so improved sealing processes are important. Product demonstrations include an 11-inch 0.3mm thick 960x540 pixel display and a 3mm thin 11-inch 940x540 display with high contrast ratio from Sony.
OLED (Organic Light Emitting Diode) is an emerging display technology that uses electroluminescence from organic compounds to emit light. OLEDs offer brighter, thinner, and more flexible displays compared to traditional LCD screens. They consist of a series of thin organic layers sandwiched between an anode and cathode, which emit light when electric current is applied. While offering benefits like high contrast and low power consumption, OLEDs currently have drawbacks such as higher costs and limited lifespan.
OLED (Organic Light Emitting Diode) is a solid state device that creates light through thin films made of organic plastics and polymers rather than metals. It was first developed in the 1950s and commercialized in the late 1980s. An OLED has several layers including an emissive layer that produces light when electric current is applied, as electrons combine with holes. OLEDs can be either active or passive, with active using TFT backplanes and suitable for large screens while passive intersect perpendicularly and are best for small screens. OLEDs offer advantages like flexibility, thinness, wide viewing angles and low energy use, but also have challenges including short blue light lifespan and higher production costs compared to
Organic Light Emitting Diode or OLED
An OLED is a solid state device or electronic device that typically consists of organic thin films sandwiched between two thin film conductive electrodes. When electrical current is applied, a bright light is emitted. OLED use a carbon-based designer molecule that emits light when an electric current passes through it. This is called electrophosphorescence. Even with the layered system, these systems are thin . usually less than 500 nm or about 200 times smaller than a human hair.
OLED (organic light-emitting diode) is a light-emitting diode that uses organic compounds to emit light. An OLED consists of a substrate, anode, organic layers, cathode. The organic layers emit light when electric current is applied. OLEDs have advantages over LCDs like being thinner, more flexible, requiring no backlight, and having wider viewing angles. However, blue OLEDs have shorter lifetimes currently. Future applications include transparent or flexible OLEDs in devices like phones, TVs, cars and clothing.
The document provides information about OLED display technology. It begins with an introduction to OLEDs, explaining that they are made of organic carbon-based films sandwiched between electrodes that emit light when electric current is applied. It then discusses the basic components and working principle of OLEDs, including the layers involved and how electrons and holes recombine to produce light. The document also outlines the different types of OLED displays, including passive matrix OLEDs, active matrix OLEDs, and transparent OLEDs. It provides details on each type and their uses and efficiencies.
The document discusses organic light-emitting diodes (OLEDs), which are thin films of organic compounds that emit light when electric current is applied. It provides a brief history of OLED development from the 1950s and describes the basic working principle of OLEDs involving organic semiconductor layers and electrodes. The document also outlines different types of OLEDs and their applications, as well as advantages such as high contrast, flexibility, and energy efficiency compared to LCDs. Potential disadvantages discussed include higher manufacturing costs and limited lifespan.
This document discusses OLED technology and provides details about its history, structure, types, advantages and applications. It begins with an introduction to OLEDs, explaining that they are thin, solid-state devices that emit light when electricity is applied. The document then covers the history of OLED development from 1987 to present, describes the layered structure of an OLED device, and discusses different methods for fabricating red, green and blue OLED pixels. In closing, the document outlines major applications of OLEDs in devices like TVs, phones and laptops and concludes that OLED displays are becoming the next generation display technology.
OLED (organic light emitting diode) technology provides better picture quality, sleeker designs, and lower cost compared to LED/LCD displays by being self-emitting. It was first observed that certain organic materials emitted light when an electric current was passed through them. There are different types of OLED displays like passive-matrix, active-matrix, transparent, and foldable. While OLEDs provide advantages like thinness, light weight, wide viewing angles and low power consumption, challenges remain around limited material lifetimes, sensitivity to water, and patent restrictions. Future areas of focus include higher efficiency micro displays, dual-sided displays, and overcoming material roadblocks.
This document provides an overview of organic light emitting diode (OLED) technology. It discusses the structure of an OLED, which consists of an organic layer sandwiched between an anode and cathode. When voltage is applied, electrons and holes combine in the organic layer to emit light. OLEDs are self-emitting so they do not require backlights like LCDs. The document outlines OLED deposition methods like evaporation and inkjet printing and compares OLED and LCD displays. It also discusses the advantages of OLEDs like flexibility and high contrast, as well as applications in devices like phones, TVs and lights.
This document discusses organic light-emitting diodes (OLEDs). It defines OLEDs as thin, light-emitting diodes that consist of organic compounds that emit light when electric current is passed through them. The document describes the layers that make up an OLED, including the substrate, anode, organic layers, and cathode. It also classifies OLEDs based on transparency and pixel formation and discusses some applications of OLEDs such as in televisions, keyboards, and lighting. Finally, it compares OLEDs to other display and lighting technologies and outlines some advantages and challenges of OLEDs.
The document discusses OLED (organic light-emitting diode) technology. OLEDs are thin, light-emitting diodes made by placing a film of organic material between two conductors. When electric current is applied, electrons from one side recombine with electron holes on the other side, releasing energy in the form of light. OLEDs can be used to create bright, flexible, energy-efficient displays. They are being used increasingly in devices like phones, TVs, and digital cameras due to advantages like thinness, light weight, wide viewing angles, and low power consumption. However, challenges remain in improving the lifetime of blue OLED materials and reducing manufacturing costs.
This document discusses OLED technology. It begins by introducing OLEDs and their use in displays, noting their advantages over LCDs like being thinner, brighter, and more flexible. It then describes the basic structure and working principle of OLEDs, including the organic layers and electroluminescence. Examples are given of different types of OLEDs and their applications. In conclusion, it states that OLED displays are emerging as the next generation display technology and could improve on limitations of LCDs.
OLED - Organic Light Emitting Diode
Today's most rapidly growing technology in World
All display technology now change to OLED
Less Power consumption
Cost Effective
Flexible
Environment Friendly
OLEDs (organic light-emitting diodes) operate similarly to traditional LEDs but use organic compounds rather than inorganic semiconductor materials. Excitons form when electrons and holes combine in the emissive layer. These excitons can then transfer their energy to fluorescent or phosphorescent molecules attached to polymers, causing the molecules to emit light as they return to the ground state. This indirect light emission mechanism greatly increases the probability of light being generated per exciton. OLEDs have advantages over traditional displays in being thinner, more flexible, and easier to fabricate due to the soft organic materials used. Research continues to improve OLED efficiency and develop new materials.
this presentation is about OLED(organic light emitting diode) technology.It involves how oleds works,the types of oled and their mechanisms,advantages,disadvantages,applications
OLEDs emit light when electricity is applied to a film of organic material. They have faster response times than LEDs and can be made transparent or flexible. An OLED is made of an emissive organic layer sandwiched between a cathode and anode. When voltage is applied, electrons from the cathode combine with holes from the anode in the emissive layer, emitting light. OLEDs are being used in TVs, phones, and other devices but have shorter lifetimes than LEDs, especially for blue colors.
The document discusses organic light emitting diodes (OLEDs), which are thin, light-emitting devices composed of organic material. It provides a history of OLED development, describes how OLEDs work through electroluminescence without the need for backlighting, and covers manufacturing methods. The document also examines different types of OLEDs including passive matrix, active matrix, and transparent OLEDs. It outlines advantages such as thinness, flexibility, high contrast, and wide viewing angles, as well as challenges including short blue light lifespan. Applications mentioned include use of OLEDs in televisions, mobile phones, and smart watches.
OLED (organic light-emitting diode) is a light-emitting diode made by placing a series of organic thin films between two conductors. When electrical current is applied, a bright light is emitted from a device that is 100 to 500 nm thick. There are different types of OLEDs including passive matrix OLEDs, active matrix OLEDs, and foldable OLEDs. OLEDs have advantages over traditional lighting like being lightweight, thin, flexible, more energy efficient, and having faster response times. However, their manufacturing processes are currently expensive and their organic materials have limited lifetimes. OLEDs are used in displays for phones, TVs, watches and can potentially replace traditional light bulbs
This document summarizes key aspects of OLED (Organic Light Emitting Diode) technology. OLEDs were first created in 1987 and have several advantages over other display technologies like LCDs, including faster response times, lower energy consumption, thinner displays, and wider viewing angles. The document describes the architecture of OLEDs including organic layers, substrates, and electrodes. It also discusses different types like passive matrix, active matrix, transparent, and foldable OLEDs. Current research is focused on improving efficiency and reducing manufacturing costs. OLED applications include TVs, phones, lighting, and future uses may include flexible and transparent displays.
This document provides information about various sensors and integrated circuits (ICs), including their technologies and applications. It discusses photo sensors, IR sensors, motor driver ICs, and soil moisture sensors. It describes how photo sensors work using light sources, receivers and signal converters to detect changes in light intensity. It outlines different sensing modes for photo sensors including diffused, retro-reflective, and thru-beam. It also discusses integrated circuits, how they are made and their revolutionary impact on electronics and modern society.
1. The document discusses the history and development of artificial eyes and bionic eyes. It describes how early artificial eyes were made of glass or plastic to replace structures in the eye socket.
2. Modern bionic eyes work by implanting microchips or ceramic detectors behind the retina to stimulate nerves and transmit signals to the brain to interpret images. Surgery involves precise insertion of these devices through small incisions.
3. The goal is to restore vision for conditions like macular degeneration and retinitis pigmentosa by bypassing damaged photoreceptor cells and stimulating optic nerves directly with signals from the artificial device. This technology remains in development with the aim of helping millions of people with vision loss.
OLED (Organic Light Emitting Diode) is a solid state device that creates light through thin films made of organic plastics and polymers rather than metals. It was first developed in the 1950s and commercialized in the late 1980s. An OLED has several layers including an emissive layer that produces light when electric current is applied, as electrons combine with holes. OLEDs can be either active or passive, with active using TFT backplanes and suitable for large screens while passive intersect perpendicularly and are best for small screens. OLEDs offer advantages like flexibility, thinness, wide viewing angles and low energy use, but also have challenges including short blue light lifespan and higher production costs compared to
Organic Light Emitting Diode or OLED
An OLED is a solid state device or electronic device that typically consists of organic thin films sandwiched between two thin film conductive electrodes. When electrical current is applied, a bright light is emitted. OLED use a carbon-based designer molecule that emits light when an electric current passes through it. This is called electrophosphorescence. Even with the layered system, these systems are thin . usually less than 500 nm or about 200 times smaller than a human hair.
OLED (organic light-emitting diode) is a light-emitting diode that uses organic compounds to emit light. An OLED consists of a substrate, anode, organic layers, cathode. The organic layers emit light when electric current is applied. OLEDs have advantages over LCDs like being thinner, more flexible, requiring no backlight, and having wider viewing angles. However, blue OLEDs have shorter lifetimes currently. Future applications include transparent or flexible OLEDs in devices like phones, TVs, cars and clothing.
The document provides information about OLED display technology. It begins with an introduction to OLEDs, explaining that they are made of organic carbon-based films sandwiched between electrodes that emit light when electric current is applied. It then discusses the basic components and working principle of OLEDs, including the layers involved and how electrons and holes recombine to produce light. The document also outlines the different types of OLED displays, including passive matrix OLEDs, active matrix OLEDs, and transparent OLEDs. It provides details on each type and their uses and efficiencies.
The document discusses organic light-emitting diodes (OLEDs), which are thin films of organic compounds that emit light when electric current is applied. It provides a brief history of OLED development from the 1950s and describes the basic working principle of OLEDs involving organic semiconductor layers and electrodes. The document also outlines different types of OLEDs and their applications, as well as advantages such as high contrast, flexibility, and energy efficiency compared to LCDs. Potential disadvantages discussed include higher manufacturing costs and limited lifespan.
This document discusses OLED technology and provides details about its history, structure, types, advantages and applications. It begins with an introduction to OLEDs, explaining that they are thin, solid-state devices that emit light when electricity is applied. The document then covers the history of OLED development from 1987 to present, describes the layered structure of an OLED device, and discusses different methods for fabricating red, green and blue OLED pixels. In closing, the document outlines major applications of OLEDs in devices like TVs, phones and laptops and concludes that OLED displays are becoming the next generation display technology.
OLED (organic light emitting diode) technology provides better picture quality, sleeker designs, and lower cost compared to LED/LCD displays by being self-emitting. It was first observed that certain organic materials emitted light when an electric current was passed through them. There are different types of OLED displays like passive-matrix, active-matrix, transparent, and foldable. While OLEDs provide advantages like thinness, light weight, wide viewing angles and low power consumption, challenges remain around limited material lifetimes, sensitivity to water, and patent restrictions. Future areas of focus include higher efficiency micro displays, dual-sided displays, and overcoming material roadblocks.
This document provides an overview of organic light emitting diode (OLED) technology. It discusses the structure of an OLED, which consists of an organic layer sandwiched between an anode and cathode. When voltage is applied, electrons and holes combine in the organic layer to emit light. OLEDs are self-emitting so they do not require backlights like LCDs. The document outlines OLED deposition methods like evaporation and inkjet printing and compares OLED and LCD displays. It also discusses the advantages of OLEDs like flexibility and high contrast, as well as applications in devices like phones, TVs and lights.
This document discusses organic light-emitting diodes (OLEDs). It defines OLEDs as thin, light-emitting diodes that consist of organic compounds that emit light when electric current is passed through them. The document describes the layers that make up an OLED, including the substrate, anode, organic layers, and cathode. It also classifies OLEDs based on transparency and pixel formation and discusses some applications of OLEDs such as in televisions, keyboards, and lighting. Finally, it compares OLEDs to other display and lighting technologies and outlines some advantages and challenges of OLEDs.
The document discusses OLED (organic light-emitting diode) technology. OLEDs are thin, light-emitting diodes made by placing a film of organic material between two conductors. When electric current is applied, electrons from one side recombine with electron holes on the other side, releasing energy in the form of light. OLEDs can be used to create bright, flexible, energy-efficient displays. They are being used increasingly in devices like phones, TVs, and digital cameras due to advantages like thinness, light weight, wide viewing angles, and low power consumption. However, challenges remain in improving the lifetime of blue OLED materials and reducing manufacturing costs.
This document discusses OLED technology. It begins by introducing OLEDs and their use in displays, noting their advantages over LCDs like being thinner, brighter, and more flexible. It then describes the basic structure and working principle of OLEDs, including the organic layers and electroluminescence. Examples are given of different types of OLEDs and their applications. In conclusion, it states that OLED displays are emerging as the next generation display technology and could improve on limitations of LCDs.
OLED - Organic Light Emitting Diode
Today's most rapidly growing technology in World
All display technology now change to OLED
Less Power consumption
Cost Effective
Flexible
Environment Friendly
OLEDs (organic light-emitting diodes) operate similarly to traditional LEDs but use organic compounds rather than inorganic semiconductor materials. Excitons form when electrons and holes combine in the emissive layer. These excitons can then transfer their energy to fluorescent or phosphorescent molecules attached to polymers, causing the molecules to emit light as they return to the ground state. This indirect light emission mechanism greatly increases the probability of light being generated per exciton. OLEDs have advantages over traditional displays in being thinner, more flexible, and easier to fabricate due to the soft organic materials used. Research continues to improve OLED efficiency and develop new materials.
this presentation is about OLED(organic light emitting diode) technology.It involves how oleds works,the types of oled and their mechanisms,advantages,disadvantages,applications
OLEDs emit light when electricity is applied to a film of organic material. They have faster response times than LEDs and can be made transparent or flexible. An OLED is made of an emissive organic layer sandwiched between a cathode and anode. When voltage is applied, electrons from the cathode combine with holes from the anode in the emissive layer, emitting light. OLEDs are being used in TVs, phones, and other devices but have shorter lifetimes than LEDs, especially for blue colors.
The document discusses organic light emitting diodes (OLEDs), which are thin, light-emitting devices composed of organic material. It provides a history of OLED development, describes how OLEDs work through electroluminescence without the need for backlighting, and covers manufacturing methods. The document also examines different types of OLEDs including passive matrix, active matrix, and transparent OLEDs. It outlines advantages such as thinness, flexibility, high contrast, and wide viewing angles, as well as challenges including short blue light lifespan. Applications mentioned include use of OLEDs in televisions, mobile phones, and smart watches.
OLED (organic light-emitting diode) is a light-emitting diode made by placing a series of organic thin films between two conductors. When electrical current is applied, a bright light is emitted from a device that is 100 to 500 nm thick. There are different types of OLEDs including passive matrix OLEDs, active matrix OLEDs, and foldable OLEDs. OLEDs have advantages over traditional lighting like being lightweight, thin, flexible, more energy efficient, and having faster response times. However, their manufacturing processes are currently expensive and their organic materials have limited lifetimes. OLEDs are used in displays for phones, TVs, watches and can potentially replace traditional light bulbs
This document summarizes key aspects of OLED (Organic Light Emitting Diode) technology. OLEDs were first created in 1987 and have several advantages over other display technologies like LCDs, including faster response times, lower energy consumption, thinner displays, and wider viewing angles. The document describes the architecture of OLEDs including organic layers, substrates, and electrodes. It also discusses different types like passive matrix, active matrix, transparent, and foldable OLEDs. Current research is focused on improving efficiency and reducing manufacturing costs. OLED applications include TVs, phones, lighting, and future uses may include flexible and transparent displays.
This document provides information about various sensors and integrated circuits (ICs), including their technologies and applications. It discusses photo sensors, IR sensors, motor driver ICs, and soil moisture sensors. It describes how photo sensors work using light sources, receivers and signal converters to detect changes in light intensity. It outlines different sensing modes for photo sensors including diffused, retro-reflective, and thru-beam. It also discusses integrated circuits, how they are made and their revolutionary impact on electronics and modern society.
1. The document discusses the history and development of artificial eyes and bionic eyes. It describes how early artificial eyes were made of glass or plastic to replace structures in the eye socket.
2. Modern bionic eyes work by implanting microchips or ceramic detectors behind the retina to stimulate nerves and transmit signals to the brain to interpret images. Surgery involves precise insertion of these devices through small incisions.
3. The goal is to restore vision for conditions like macular degeneration and retinitis pigmentosa by bypassing damaged photoreceptor cells and stimulating optic nerves directly with signals from the artificial device. This technology remains in development with the aim of helping millions of people with vision loss.
The document summarizes a seminar about a hollow flashlight device that harvests energy from human body heat using the Peltier effect. The flashlight contains Peltier tiles mounted on a hollow aluminum tube, with one side heated by a person's hand holding the tube. This creates a temperature differential that the Peltier tiles convert into electricity using thermoelectric effect. This harvested energy from body heat is enough to power an LED light for over 20 minutes. The flashlight provides an advantage over batteries by providing clean, renewable energy from waste heat without using chemicals. Researchers are exploring ways to power small devices like hearing aids using excess body heat.
Final aartifical eye seminar report march2016gautam221094
This document is a seminar report submitted by Arjun Ram on the topic of artificial eyes, also known as bionic eyes. It provides an overview of the human eye and various eye conditions that can lead to vision loss. It discusses the history of artificial eyes from early glass and plastic prosthetics to current developments in bionic eyes. The report covers various bionic eye technologies such as the artificial silicon retina and MARC system. It describes the working, implantation process, and manufacturing of bionic eyes, which aim to restore sight to the blind.
This document provides an overview of hybrid electric vehicles (HEVs). It discusses the components and working of HEVs, including how the internal combustion engine and electric motor work together to propel the vehicle using both gasoline and electric power. It also covers the different levels and configurations of hybrid systems, from full hybrids that can run solely on electric power to mild hybrids. The document aims to explain HEV technology and its benefits over conventional vehicles in improving fuel efficiency and reducing emissions.
The document describes a heat-powered flashlight called The Hallow that uses a patent-pending design incorporating Peltier tiles. The flashlight generates electricity from the difference in temperature between the user's body heat and the cooler outside of the flashlight body. This allows it to produce a steady beam of LED light for 20 minutes with only body heat as an energy source, though its brightness of 24 lumens is less than commercial flashlights that can output dozens or hundreds of lumens. The inventor still needs to secure the patent and further refine the prototype before bringing it to market.
The microelectronic pill is a multichannel sensor that is 16mm in diameter, 55mm long, and weighs 5 grams. It contains sensors, an application specific integrated circuit (ASIC) to connect components, and a transmitter powered by two silver oxide batteries. The pill can measure body temperature, pH, conductivity, and dissolved oxygen through its sensors. It transmits sensor data at 1 kbps for over 40 hours on its batteries while consuming only 12.1mW of power. The microelectronic pill allows for disease detection and monitoring inside the human body with low power usage and size suitable for practical applications.
Wireless electronic notice board using gsm technolgydhanshri_deshmukh
This document discusses the design of a wireless electronic notice board using GSM technology. It begins with introductions to GSM and embedded systems. It then shows the block diagram of the notice board, which includes a GSM modem connected to a microcontroller that controls an LCD display. The document discusses the history and services of GSM networks. It provides details on the architecture of GSM networks and their components like the mobile station, base station subsystem, and network subsystem.
These slides use concepts from my (Jeff Funk) course entitled analyzing hi-tech opportunities to analyze how the economic feasibility of flexible OLED displays are becoming better through newer and thinner materials, roll-to roll printing, and larger production equipment. Thinner materials along with new materials increase flexibility, reduce moisture permeation and thus increase the lifetime, and reduce cost. Flexibility enables displays that conform to complex shaped things such as wrists and backpacks and that can be fit inside pens and other tubes. Along with other technologies, this further facilitates information access.
The document summarizes Ann Makosinski's invention of the Hollow Flashlight, which harnesses body heat through Peltier tiles to power an LED light without batteries. The flashlight uses four Peltier tiles mounted on an aluminum tube within a PVC pipe to convert the temperature difference between a person's hand and ambient air into electricity. This temperature difference produces enough power for the LED light to shine continuously for over 20 minutes. Researchers see potential for this design to power small devices sustainably using human body heat rather than batteries.
Can we just imagine of having a TV which can be rolled up? Wouldn’t you like to be able to read off the screen of your laptop in direct sunlight? Your mobile phone battery to last much, much longer? Or your next flat screen TV to be less expensive, much flatter, and even flexible? Well, now it is possible by an emerging technology based on the revolutionary discovery that, light emitting, fast switching diode could be made from polymers as well as semiconductors.OLED
This document is a seminar report on organic light-emitting diode (OLED) displays submitted by Vishnu S.S. to the Department of Electronics and Communication at Government Polytechnic College in Neyyattinkara, India in 2017. The report provides an introduction to OLEDs, discusses their history and components. It also describes the fabrication process and methods of OLEDs and examines their working principle, types, advantages and applications. The report aims to inform readers about OLED displays and their potential as an emerging display technology.
The document summarizes a seminar on artificial eyes presented by Jamvant Sonwane. It discusses how natural eyes work using rods and cones, common eye diseases like age-related macular degeneration and retinal pigmentosa. It then explains that an artificial eye uses a camera, microchip, and retinal implant to provide vision by stimulating the retina and optic nerve. The seminar describes the components and working of artificial eyes, comparing natural and artificial vision. It also outlines the limitations of current artificial eye technology.
hey guyz this is the presentation iv made in my last year of engineering and got very nice feedbacks. my topic was oled(organic light emitting diodes).. iv given all its highlited informations with pictures
This document is a project report on e-business submitted by Pramod Verma to fulfill requirements for a Master's degree in management studies. The report includes an introduction, literature review, methodology, objectives and scope of e-business. It discusses types of e-business transactions including B2B, B2C, C2C and others. It also covers advantages and limitations of e-business, and factors for e-business success and failure. The report aims to understand e-business and provide guidance to make an IT employment website successful.
A seminar report on hybrid electric vehicle007skpk
This document is a seminar report submitted by Sanjay Kumar Yadav to fulfill the requirements for a Bachelor of Technology degree in Electrical Engineering. The report discusses hybrid electric vehicles, including their technical workings, advantages, disadvantages, and policy considerations. It provides an overview of hybrid electric vehicle technology, comparisons to other vehicle technologies like compressed natural gas vehicles and clean diesel vehicles, and the role of fuel quality. The report aims to guide policymakers in developing and transitional countries on enabling greater vehicle efficiency.
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This document provides tips to avoid common mistakes in PowerPoint presentation design. It identifies the top 5 mistakes as including putting too much information on slides, not using enough visuals, using poor quality or unreadable visuals, having messy slides with poor spacing and alignment, and not properly preparing and practicing the presentation. The document encourages presenters to use fewer words per slide, high quality images and charts, consistent formatting, and to spend significant time crafting an engaging narrative and rehearsing their presentation. It emphasizes that an attractive design is not as important as being an effective storyteller.
This document provides an introduction to organic light-emitting diodes (OLEDs). It describes OLEDs as thin, flexible displays that are self-luminous and more energy efficient than LCD displays. The document discusses the components and manufacturing of OLEDs. It explains that OLEDs work by emitting light through a process called electrophosphorescence when electricity is applied. Different types of OLEDs are described, including passive matrix OLEDs best for small screens, and active matrix OLEDs more suitable for large displays. Advantages of OLEDs over LCDs are highlighted as lower power consumption, higher power efficiency, and less power needed to produce the same brightness.
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(1) OLEDs are light emitting diodes that use organic compounds that emit light in response to an electric current. (2) They are used in digital displays like TVs, phones, and tablets and can be thinner, lighter, and use less power than LCD displays. (3) Research is focused on improving the lifespan of blue OLEDs and developing cheaper manufacturing methods like roll-to-roll production to increase their use in displays and solid-state lighting.
Organic electronics is an emerging field with an unimaginable future.I have included nutshell of applications and future scope in this field.Think it will be helpful for engineering aspirants.
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organic electronics & it's application (OLEDs and it's types) difference between OLEDs, LCD and LED. How OLEDs leads the other lighting or display devices.
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OLED: Organic Light Emitting Device
1. 1
OLED
ABSTRACT
Over the time there are many changes came into the field of output/display devices. In this field
first came the small led displays which can show only the numeric contents. Then came the
heavy jumbo CRTs (Cathode Ray Tubes) which are used till now. But the main problem with
CRT is they are very heavy & we couldn’t carry them from one place to another. The result of
this CRT is very nice & clear but they are very heavy & bulky & also required quiet large area
than anything else. Then came the very compact LCDs (Liquefied Crystal Displays). They are
very lighter in weight as well as easy to carry from one place to the other. But the main problem
with the LCDs is we can get the perfect result in the some particular direction. If we see from
any other direction it will not display the perfect display. To overcome this problems of CRTs &
LCDs the scientist of Universal Laboratories, Florida, United States & Eastman Kodak Company
both started their research work in that direction & the outcome of their efforts is the new
generation of display technologies named OLED (Organic Light Emitting Diode) Technology. In
the flat panel display zone unlike traditional Liquid-Crystal Displays OLEDs are self luminous &
do not require any kind of backlighting. This eliminates the need for bulky & environmentally
undesirable mercury lamps and yields a thinner, more compact display. Unlike other flat panel
displays OLED has a wide viewing angle (up to 160 degrees), even in bright light. Their low
power consumption (only 2 to 10 volts) provides for maximum efficiency and helps minimize
heat and electric interference in electronic devices. Because of this combination of these features,
OLED displays communicate more information in a more engaging way while adding less
weight and taking up less space. Their application in numerous devices is not only a future
possibility but a current reality.
2. 2
LIST OF FIGURES
Figure 1. Demonstration of flexible OLED device 9
Figure 2. Structure of OLED 12
Figure 3. Triplet state 14
Figure 4. Two different way of decay 15
Figure 5. Single organic layer 16
Figure 6. Two organic layer 17
Figure 7. Multilayer organic light emitting diode 17
Figure 8. Recombination region 19
Figure 9. Layer sequence and energy level diagram for OLED 21
Figure 10. OLED Passive matrix 23
5. 5
TABLE OF CONTENTS
Page no.
Certificate..........................................................................................................................ii
Abstract ............................................................................................................................iii
Acknowledgment..............................................................................................................iv
List of Figure ....................................................................................................................vii
List of Table ......................................................................................................................ix
(1) Introduction………………………………………………………………………....8
(2) History……………………………………………………………………………….10
(3) Components of an OLED…………………………………………………………..12
(4) Working Operation………………………………………………………………....14
(5) Types of OLED……………………………………………………………………..22
(6) OLED and LCD comparison…………………........................................................28
(7) Advantages………………………………………………………………………….30
(8) Disadvantages…………………………………………………………………….....31
(9) Current and future OLED Applications………………………………………….33
(10) Efficiency of OLED………………………………………………………………..36
(11) The Organic Future………………………………………………………………..37
(12) Conclusion……………………………………………………………………….....38
References………………………………………………………………………….39
6. 6
INTRODUCTION
Scientific research in the area of semiconducting organic materials as the active substance in
light emitting diodes (LEDs) has increased immensely during the last four decades. Organic
semiconductors was first reported in the 60:s and then the materials were only considered to be
merely a scientific curiosity. (They are named organic because they consist primarily of carbon,
hydrogen and oxygen.). However when it was recognized in the eighties that many of them are
photoconductive under visible light, industrial interests were attracted. Many major electronic
companies, such as Philips and Pioneer, are today investing a considerable amount of money in
the science of organic electronic and optoelectronic devices. The major reason for the big
attention to these devices is that they possibly could be much more efficient than today’s
components when it comes to power consumption and produced light. Common light emitters
today, Light Emitting Diodes (LEDs) and ordinary light bulbs consume more power than organic
diodes do. And the strive to decrease power consumption is always something of matter. Other
reasons for the industrial attention are i.e. that eventually organic full color displays will replace
today’s liquid crystal displays (LCDs) used in laptop computers and may even one day replace
our ordinary CRT-screens.
Organic light-emitting devices (OLEDs) operate on the principle of converting
electrical energy into light, a phenomenon known as electroluminescence. They exploit the
properties of certain organic materials which emit light when an electric current passes through
them. In its simplest form, an OLED consists of a layer of this luminescent material sandwiched
between two electrodes. When an electric current is passed between the electrodes, through the
organic layer, light is emitted with a colour that depends on the particular material used. In order
to observe the light emitted by an OLED, at least one of the electrodes must be transparent.
When OLEDs are used as pixels in flat panel displays they have some advantages
over backlit active-matrix LCD displays - greater viewing angle, lighter weight, and quicker
response. Since only the part of the display that is actually lit up consumes power, the most
efficient OLEDs available today use less power.
7. 7
Figure.1 Demonstration of a flexible OLED device
Based on these advantages, OLEDs have been proposed for a wide range of display
applications including magnified micro displays, wearable, head-mounted computers, digital
cameras, personal digital assistants, smart pagers, virtual reality games, and mobile phones as
well as medical, automotive, and other industrial applications.
8. 8
HISTORY
The first observations of electroluminescence in organic materials were in the early 1950s by
André Bernanose and co-workers at the Nancy-Université, France. They applied high-
voltage alternating current (AC) fields in air to materials such as acridine orange, either
deposited on or dissolved in cellulose or cellophane thin films. The proposed mechanism was
either direct excitation of the dye molecules or excitation of electrons.
In 1960, Martin Pope and co-workers at New York University developed ohmic dark-
injecting electrode contacts to organic crystals. They further described the necessary energetic
requirements (work functions) for hole and electron injecting electrode contacts. These contacts
are the basis of charge injection in all modern OLED devices. Pope's group also first observed
direct current (DC) electroluminescence under vacuum on a pure single crystal of anthracene and
on anthracene crystals doped with tetracene in 1963 using a small area silver electrode at 400 V.
The proposed mechanism was field-accelerated electron excitation of molecular fluorescence.
Pope's group reported in 1965 that in the absence of an external electric field, the
electroluminescence in anthracene crystals is caused by the recombination of a thermalized
electron and hole, and that the conducting level of anthracene is higher in energy than the exciton
energy level. Also in 1965, W. Helfrich and W. G. Schneider of the National Research
Council in Canada produced double injection recombination electroluminescence for the first
time in an anthracene single crystal using hole and electron injecting electrodes, the forerunner
of modern double injection devices. In the same year, Dow Chemical researchers patented a
method of preparing electroluminescent cells using high voltage (500–1500 V) AC-driven (100–
3000 Hz) electrically insulated one millimeter thin layers of a melted phosphor consisting of
ground anthracene powder, tetracene, and graphite powder. Their proposed mechanism
involved electronic excitation at the contacts between the graphite particles and the anthracene
molecules.
Electroluminescence from polymer films was first observed by Roger Partridge at
the National Physical Laboratory in the United Kingdom. The device consisted of a film of
poly(n-vinylcarbazole) up to 2.2 micrometers thick located between two charge injecting
electrodes. The results of the project were patented in 1975 and published in 1983.
9. 9
The first diode device was reported at Eastman Kodak by Ching W. Tang and Steven
Van Slyke in 1987. This device used a novel two-layer structure with separate hole transporting
and electron transporting layers such that recombination and light emission occurred in the
middle of the organic layer. This resulted in a reduction in operating voltage and improvements
in efficiency and led to the current era of OLED research and device production.
Research into polymer electroluminescence culminated in 1990 with J. H. Burroughes et
al. at the Cavendish Laboratory in Cambridge reporting a high efficiency green light-emitting
polymer based device using 100 nm thick films of poly(p-phenylene vinylene).
10. 10
COMPONENTS OF AN OLED
The components in an OLED differ according to the number of layers of the organic material.
There is a basic single layer OLED, two layer and also three layer OLED’s. As the number of
layers increase the efficiency of the device also increases. The increase in layers also helps in
injecting charges at the electrodes and thus helps in blocking a charge from being dumped after
reaching the opposite electrode. Any type of OLED consists of the following components.
1. An emissive layer
2. A conducting layer
3. A substrate
4. Anode and cathode terminals.
Figure.2 Stucture of OLED
Substrate- The substrate supports the OLED.
Example: clear plastic, glass, foil.
11. 11
Anode- The anode removes electrons when current flows through the device.
Example: indium tin oxide
Organic layers- These layers are made of organic molecules or polymers.
o Conductive layer- This layer is made of organic plastic molecules that
send electrons out from the anode.
Example: polyaniline, polystyrene
o Emissive layer- This layer is made of organic plastic molecules
(different ones from the conducting layer) that transport electrons from
the cathode; this is where light is made.
Example: polyfluorine, Alq3
Cathode- The cathode injects electrons when a current flows through the device. (It may
or may not be transparent depending on the device)
Example: Mg, Al, Ba, Ca
12. 12
WORKING OPERATION
The organic light emitting diode (OLED) is a p-n diode, in which charge-carriers (e-h pairs)
recombine to emit photons in an organic layer. The thickness of this layer is approximately 100
nm (experiments have shown that 70 nm is an optimal thickness). When an electron and a hole
recombine, an excited state called an exciton is formed. Depending on the spin of the e-h pair,
the excitation is either a singlet or a triplet. An electron can have two different spins, spin up and
spin down. When the spin of two particles is the same, they are said to be in a spin-paired, or a
triplet state, and when the spin is opposite they are in a spin-paired singlet state.
Figure.3 Triplet State
On the average, one singlet and three triplets are formed for every four electron-hole pairs, and
this is a big inefficiency in the operation of the diodes. A singlet state decays very quickly,
within a few nanoseconds, and thereby emits a photon in a process called fluorescence. A triplet
state, however, is much more long-lived (1 ms - 1 s), and generally just produce heat. One
method of improving the performance is to add a phosphorescent material to one of the layers in
13. 13
the OLED. This is done by adding a heavy metal such as iridium or platinum. The excitation can
then transfer its energy to a phosphorescent molecule which in turn emits a photon. It is however
a problem that few phosphorescent materials are efficient emitters at room temperature.
Figure.4 Two different ways of decay
There have been devices manufactured which transforms both singlet and triplet states in a host
to a singlet state in the fluorescent dye. This is done by using a phosphorescent compound which
both the singlets and triplets transfer their energy to, after which the compound transfer its
energy to a fluorescent material which then emits light.
Using one organic layer has some problems associated with it. The electrodes energy
levels have to be matched very closely, otherwise the electron and hole currents will not be
properly balanced. This leads to a waste in energy since charges can then pass the entire structure
14. 14
without recombining, and this lowers the efficiency of the device. With two organic layers, the
situation improves dramatically. Now the different layers can be optimized for the electrons and
holes respectively. The charges are blocked at the interface of the materials, and “waits” there for
a “partner”.
Figure.5 Single Organic layer
Considerably better balance can be achieved by using two organic layers one of which is
matched to the anode and transports holes with the other optimized for electron injection and
transport. Each sign of charge is blocked at the interface between the two organic layers and tend
to "wait" there until a partner is found.
Recombination therefore occurs with the excitation forming in the organic material
with the lower energy gap. The fact that it forms near the interface is also beneficial in
preventing quenching of the luminescence that can occur when the excitation is near one of the
electrodes.
15. 15
Figure.6 Two Organic layers
Another improvement is to introduce a third material specifically chosen for its
luminescent efficiency. Now the three organic materials can be separately optimized for electron
transport, for hole transport and for luminescence.
Figure.7 Multilayer organic light emitting diode
The principle of operation of organic light emitting diodes (OLEDs) is similar to that of
inorganic light emitting diodes (LEDs). Holes and electrons are injected from opposite contacts
into the organic layer sequence and transported to the emitter layer. Recombination leads to the
formation of singlet excitons that decay radiatively. In more detail, electroluminescence of
16. 16
organic thin film devices can be divided into five processes that are important for device
operation:
(a) Injection: Electrons are injected from a low work function metal con-tact, e. g. Ca or Mg.
The latter is usually chosen for reasons of stability. A wide-gap transparent indium-tin-oxide
(ITO) or polyaniline thin film is used for hole injection. In addition, the efficiency of carrier
injection can be improved by choosing organic hole and electron injection layers with a low
HOMO (high occupied molecular orbital) or high LUMO (lowest unoccupied molecular orbital)
level, respectively.
(b) Transport: In contrast to inorganic semiconductors, high p- or n-conducting organic thin
films can only rarely be obtained by doping. Therefore, preferentially hole or electron
transporting organic compounds with sufficient mobility have to be used to transport the charge
carriers to the re-combination site. Since carriers of opposite polarity also migrate to some
extent, a minimum thickness is necessary to prevent non-radiative recombination at the opposite
contact. Thin electron or hole blocking layers can be inserted to improve the selective carrier
transport.
(c) Recombination: The efficiency of electron-hole recombination leading to the creation of
singlet excitons is mainly influenced by the overlap of electron and hole densities that originate
from carrier injection into the emitter layer. Recombination of filled traps and free carriers may
also attribute to the formation of excited states. Energy barriers for electrons and holes to both
sides of the emitter layer allow to spatially confine and improve the recombination process.
(d) Migration and (e) decay: Singlet excitons will migrate with an average diffusion length of
about 20 nm followed by a radiative or non-radiative decay. Embedding the emitter layer into
transport layers with higher singlet excitation energies leads to a confinement of the singlet
excitons and avoids non-radiative decay paths. Doping of the emitter layer with organic dye
molecules allows to transfer energy from the host to the guest molecule in order to tune the
emission wavelength or to increase the luminous efficiency.
17. 17
When biased, charge is injected into the highest occupied molecular
orbital (HOMO) at the anode (positive), and the lowest unoccupied molecular orbital (LUMO) at
the cathode (negative), and these injected charges (referred to as “holes” and “electrons,”
respectively) migrate in the applied field until two charges of opposite polarity encounter each
other, at which point they annihilate and produce a radiative state emitting photons with energy
hf =Eg . The energy gap is the difference between the HOMO and LUMO level of the emitting
layer, and it is largely responsible for the observed color of the light.
Figure.8 Recombination Region
19. 19
Figure.9 Layer sequences and energy level diagrams for OLEDs with (a) single layer,
(b) single hetero structure, (c) double hetero structure, and (d)multiplayer structure
with separate hole and electron injection and transport layers.
20. 20
TYPES OF OLED
There are several types of OLEDs:
Passive-matrix OLED
Active-matrix OLED
Transparent OLED
Top-emitting OLED
Foldable OLED
White OLED
Passive-matrix OLED (PMOLED)
PMOLEDs have strips of cathode, organic layers and strips of anode. The anode strips are
arranged perpendicular to the cathode strips. The intersections of the cathode and anode make up
the pixels where light is emitted. External circuitry applies current to selected strips of anode and
cathode, determining which pixels get turned on and which pixels remain off. Again, the
brightness of each pixel is proportional to the amount of applied current.
PMOLEDs are easy to make, but they consume more power than other types of OLED, mainly
due to the power needed for the external circuitry. PMOLEDs are most efficient for text and
icons and are best suited for small screens (2- to 3-inch diagonal) such as those you find in CELL
PHONES, PDA’s and MP3 Players. Even with the external circuitry, passive-matrix OLEDs
consume less battery power than the LCDs that currently power these devices.
21. 21
Figure.10 OLED Passive Matrix
Active-matrix OLED (AMOLED)
AMOLEDs have full layers of cathode, organic molecules and anode, but the anode layer
overlays a thin film transistor (TFT) array that forms a matrix. The TFT array itself is the
circuitry that determines which pixels get turned on to form an image.
AMOLEDs consume less power than PMOLEDs because the TFT array requires less
power than external circuitry, so they are efficient for large displays. AMOLEDs also have faster
refresh rates suitable for video. The best uses for AMOLEDs are computer monitors, large-
screen TVs and electronic signs or billboards.
22. 22
Figure.11 OLED Active Matrix
Transparent OLED
Transparent OLEDs have only transparent components (substrate, cathode and anode) and,
when turned off, are up to 85 percent as transparent as their substrate. When a transparent OLED
display is turned on, it allows light to pass in both directions. A transparent OLED display can be
either active- or passive-matrix. This technology can be used for heads-up displays.
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Figure.12 OLED Transparent Structure
Top-emitting OLED
Top-emitting OLEDs have a substrate that is either opaque or reflective. They are best suited to
active-matrix design. Manufacturers may use top-emitting OLED displays in SMART CARDS
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Figure.13 OLED Top-Emitting Structure
Foldable OLED
Foldable OLEDs have substrates made of very flexible metallic foils or plastics. Foldable
OLEDs are very lightweight and durable. Their use in devices such as cell phones and PDAs can
reduce breakage, a major cause for return or repair. Potentially, foldable OLED displays can be
attached to fabrics to create "smart" clothing, such as outdoor survival clothing with an
integrated computer chip, cell phone, GPS receiver and OLED display sewn into it.
Figure.14 Foldable OLED
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White OLED
White OLEDs emit white light that is brighter, more uniform and more energy efficient than that
emitted by fluorescent lights. White OLEDs also have the true-color qualities of incandescent
lighting. Because OLEDs can be made in large sheets, they can replace fluorescent lights that are
currently used in homes and buildings. Their use could potentially reduce energy costs for
lighting.
Figure.15 White OLED
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ORGANIC LED AND LIQUID CRSYTAL DISPLAY
COMPARISON
Organic LED panel Liquid Crystal Panel
A luminous form Self emission of light Back light or outside light is
necessary
Consumption of Electric
power
It is lowered to about mW
though it is a little higher
than the reflection type
liquid crystal panel
It is abundant when back light
is used
Colour Indication form The fluorescent material
of RGB is arranged in
order and or a colour filter
is used.
A colour filter is used.
High brightness 100 cd/m2 6 cd/m2
The dimension of the panel Several-inches type in the
future to about 10-inch
type.Goal
It is produced to 28-inch type in
the future to 30-inch type.Goal
Contrast 100:14 6:1
The thickness of the panel It is thin with a little over
1mm
When back light is used it is
thick with 5mm.
The mass of panel It becomes light weight
more than 1gm more than
the liquid crystal panel in
the case of one for
portable telephone
With the one for the portable
telephone.10 gm weak degree.
Answer time Several us Several ns
A wide use of temperature
range
86 *C ~ -40 *C ~ -10 *C
The corner of the view Horizontal 180 * Horizontal 120* ~ 170*
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ADVANTAGES OF OLED
The different manufacturing process of OLEDs lends itself to several advantages over flat-panel
displays made with LCD technology.
Lower cost in the future: OLEDs can be printed onto any suitable substrate by an inkjet
printer or even by screen printing, theoretically making them cheaper to produce than
LCD or plasma display. However, fabrication of the OLED substrate is more costly than
that of a TFT LCD, until mass production methods lower cost through scalability.
Light weight & flexible plastic substrates: OLED displays can be fabricated on flexible
plastic substrates leading to the possibility of flexible organic light-emitting diodes being
fabricated or other new applications such as roll-up displays embedded in fabrics or
clothing.
Wider viewing angles & improved brightness: OLEDs can enable a greater artificial
contrast ratio (both dynamic range and static, measured in purely dark conditions) and
viewing angle compared to LCDs because OLED pixels directly emit light.
Better power efficiency: LCDs filter the light emitted from a back light
Response time: OLEDs can also have a faster response time than standard LCD screens.
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DISADVANTAGES OF OLED
OLED seem to be the perfect technology for all types of displays; however, they do have some
problems, including:
Outdoor performance: As an emissive display technology, OLEDs rely completely
upon converting electricity to light, unlike most LCDs which are to some extent reflective
Power consumption: While an OLED will consume around 40% of the power of an
LCD displaying an image
Screen burn-in: Unlike displays with a common light source, the brightness of each
OLED pixel fades depending on the content displayed. The varied lifespan of the organic
dyes can cause a discrepancy between red, green, and blue intensity. This leads to image
persistence, also known as burn in
UV sensitivity: OLED displays can be damaged by prolonged exposure to UV light. The
most pronounced example of this can be seen with a near UV laser (such as a Bluray
pointer) and can damage the display almost instantly with more than 20mW leading to
dim or dead spots where the beam is focused.
Lifetime - While red and green OLED films have longer lifetimes (46,000 to 230,000
hours), blue organics currently have much shorter lifetimes (up to around 14,000 hours
Manufacturing - Manufacturing processes are expensive right now.
Color balance issues: Additionally, as the OLED material used to produce blue light
degrades significantly more rapidly than the materials that produce other colors, blue
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light output will decrease relative to the other colors of light. This differential color
output change will change the color balance of the display and is much more noticeable
than a decrease in overall luminance.
Water damage: Water can damage the organic materials of the displays. Therefore,
improved sealing processes are important for practical manufacturing. Water damage
may especially limit the longevity of more flexible displays.
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CURRENT AND FUTURE OLED APPLICATIONS
Currently, OLEDs are used in small screen devices like cell phones, digital cameras etc.
Some examples of OLED applications are as follows:
Mobile Phones- Mobile phones were the first to adopt AMOLED displays and is the
largest market for OLEDs today.
Figure.16 Samsung Galaxy Round Figure.17 Blackberry Q30
OLED TVs- OLED TVs had begun shipping in 2013 but their prices are still very high.
Figure.18 Sony XEL-1, world’s 1st OLED TV
Digital Cameras- Several compact and high-end cameras use AMOLED displays that
offer rich colors and high contrast and brightness. Kodak was the first to release a digital
camera with an OLED display in March 2003, the EasyShare LS633.
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Figure.19 Kodak LS633
OLED Lamps- OLED lamps are currently very expensive, but already several
companies are offering these in the premium lighting category.
Figure.20 Turn lights flaps
Other devices- OLEDs are also used in wrist watches, headsets, car audio systems,
remote controllers, digital photo frames and many other kinds of devices.
Future uses of OLED-
Wallpaper lighting defining new ways to light a space
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Efficiency of OLED
Recent advantages in boosting the efficiency of OLED light emission have led to the possibility
that OLEDs will find early uses in many battery-powered electronic appliances such as cell
phones, game boys and personal digital assistants. Typical external quantum efficiencies of
OLEDs made using a single fluorescent material that both conducts electrons and radiates
photons are greater than 1 percent. But by using guest-host organic material systems where the
radiative guest fluorescent or phosphorescent dye molecule is doped at low concentration into a
conducting molecular host thin film, the efficiency can be substantially increased to 10 percent
or higher for phosphorescence or up to approximately 3 percent for fluorescence.
Currently, efficiencies of the best doped OLEDs exceed that of incandescent light bulbs.
Efficiencies of 20 lumens per watt have been reported for yellow-green-emitting polymer
devices and 40 lm/W for a typical incandescent light bulb. It is reasonable to that of
fluorescent room lighting will be achieved by using phosphorescent OLEDs.
The green device which shows highest efficiency is based on factris(2-phenylpyridine)
iridium[Ir(PPY)3],a green electro phosphorescent material. Thus phosphorescent emission
originates from a long-lived triplet state.
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The Organic Future
The first products using organic displays are already being introduced into the market place. And while it
is always difficult to predict when and what future products will be introduced, many manufacturers are
now working to introduce cell phones and personal digital assistants with OLED displays within the next
one or two years. The ultimate goal of using high-efficiency, phosphorescent, flexible OLED displays in
lap top computers and even for home video applications may be no more than a few years into future.
However, there remains much to be done if organics are to establish a foothold in the display
market. Achieving higher efficiencies, lower operating voltages, and lower device life times are
all challenges still to be met. But, given the aggressive worldwide efforts in this area, emissive
organic thin films have an excellent chance of becoming the technology of choice for the next
generation of high-resolution, high-efficiency flat panel displays.
In addition to displays, there are many other opportunities for application of organic thin-film
semiconductors, but to date these have remained largely untapped. Recent results in organic
electronic technology that may soon find commercial outlets in display black planes and other
low-cost electronics.
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CONCLUSION
Performance of organic LEDs depend upon many parameters such as electron and hole
mobility, magnitude of applied field, nature of hole and electron transport layers and excited
life-times. Organic materials are poised as never before to transform the world IF circuit and
display technology. Major electronics firms are betting that the future holds tremendous
opportunity for the low cost and sometimes surprisingly high performance offered by organic
electronic and optoelectronic devices.
Organic Light Emitting Diodes are evolving as the next generation of light
sources. Presently researchers have been going on to develop a 1.5 emitting device. This
wavelength is of special interest for telecommunications as it is the low-loss wavelength for
optical fibre communications. Organic full-colour displays may eventually replace liquid crystal
displays for use with lap top and even desktop computers. Researches are going on this subject
and it is sure that OLED will emerge as future solid state light source.