Basic of semiconductors and optical propertiesKamran Ansari
This presentation explains the band structure, intrinsic semiconductor, extrinsic semiconductor, electrical conductivity, mobility, hall effect, p-n junction diode, tunnel diode and optical properties of the semiconductor.
This document discusses different types of photodetectors. It describes photoconductive detectors like light dependent resistors (LDRs) and junction photodetectors including p-n photodiodes, PIN photodiodes, avalanche photodiodes, and Schottky photodiodes. PIN photodiodes are presented as an improvement over p-n photodiodes by having a larger depletion region for higher quantum efficiency. Avalanche photodiodes provide internal gain through impact ionization. Schottky photodiodes have a high speed due to being majority carrier devices. Phototransistors are also discussed as providing gain. Applications mentioned include fiber optics, cameras, medical devices, barcodes, and security systems
The document discusses band theory of solids and semiconductor devices. It explains that in solids, discrete electron energy levels split into bands. The valence band is fully filled while the conduction band is empty or partially filled, with a band gap separating the two. Semiconductors have a smaller band gap than insulators. Intrinsic semiconductors have equal numbers of electrons and holes, while extrinsic ones are doped with impurities. PN junctions are formed by combining P-type and N-type materials and act as diodes, allowing current in one direction. Diodes have applications as rectifiers, transistors, and other devices that convert between electrical and optical signals.
1. When a P-type semiconductor is joined with an N-type semiconductor, a PN junction is formed known as a semiconductor diode.
2. Semiconductor diodes are widely used as rectifiers to convert alternating current (AC) input into direct current (DC) output.
3. In a PN junction, the diffusion of majority carriers across the junction leaves behind charged acceptor and donor ions which form an electric field called the depletion region or space charge region.
DNA biosensors use the principles of nucleic acid hybridization and have different forms including electrodes, chips, and crystals. There are three main types - optical, electrochemical, and piezoelectric biosensors. DNA probes can be immobilized onto transducer surfaces through simple adsorption onto carbon, covalent linkage to gold via alkanethiol monolayers, or using biotinylated DNA and avidin/streptavidin complexes on surfaces. The immobilization method depends on the surface and involves covalent coupling or functional group interactions.
The document discusses photodiodes and LEDs. Photodiodes are a type of photo detector that can convert light into current or voltage. They have a PN or PIN junction and operate by generating a photocurrent when photons are absorbed in the depletion region. Photodiodes are used in applications like light sensors, smoke detectors, and for measuring light intensity. LEDs are semiconductors that emit light through electroluminescence when forward biased. They have advantages over incandescent bulbs like longer lifetime and higher efficiency. LEDs find applications in devices like phones and cameras.
This presentation gives a lot of information about
Semiconductor Devices.This is presented by Rajesh Kumar Sangani from Rajiv Gandhi University of Knowledge Technologies,Basar Dist
Adilabad,A.P,India.
Basic of semiconductors and optical propertiesKamran Ansari
This presentation explains the band structure, intrinsic semiconductor, extrinsic semiconductor, electrical conductivity, mobility, hall effect, p-n junction diode, tunnel diode and optical properties of the semiconductor.
This document discusses different types of photodetectors. It describes photoconductive detectors like light dependent resistors (LDRs) and junction photodetectors including p-n photodiodes, PIN photodiodes, avalanche photodiodes, and Schottky photodiodes. PIN photodiodes are presented as an improvement over p-n photodiodes by having a larger depletion region for higher quantum efficiency. Avalanche photodiodes provide internal gain through impact ionization. Schottky photodiodes have a high speed due to being majority carrier devices. Phototransistors are also discussed as providing gain. Applications mentioned include fiber optics, cameras, medical devices, barcodes, and security systems
The document discusses band theory of solids and semiconductor devices. It explains that in solids, discrete electron energy levels split into bands. The valence band is fully filled while the conduction band is empty or partially filled, with a band gap separating the two. Semiconductors have a smaller band gap than insulators. Intrinsic semiconductors have equal numbers of electrons and holes, while extrinsic ones are doped with impurities. PN junctions are formed by combining P-type and N-type materials and act as diodes, allowing current in one direction. Diodes have applications as rectifiers, transistors, and other devices that convert between electrical and optical signals.
1. When a P-type semiconductor is joined with an N-type semiconductor, a PN junction is formed known as a semiconductor diode.
2. Semiconductor diodes are widely used as rectifiers to convert alternating current (AC) input into direct current (DC) output.
3. In a PN junction, the diffusion of majority carriers across the junction leaves behind charged acceptor and donor ions which form an electric field called the depletion region or space charge region.
DNA biosensors use the principles of nucleic acid hybridization and have different forms including electrodes, chips, and crystals. There are three main types - optical, electrochemical, and piezoelectric biosensors. DNA probes can be immobilized onto transducer surfaces through simple adsorption onto carbon, covalent linkage to gold via alkanethiol monolayers, or using biotinylated DNA and avidin/streptavidin complexes on surfaces. The immobilization method depends on the surface and involves covalent coupling or functional group interactions.
The document discusses photodiodes and LEDs. Photodiodes are a type of photo detector that can convert light into current or voltage. They have a PN or PIN junction and operate by generating a photocurrent when photons are absorbed in the depletion region. Photodiodes are used in applications like light sensors, smoke detectors, and for measuring light intensity. LEDs are semiconductors that emit light through electroluminescence when forward biased. They have advantages over incandescent bulbs like longer lifetime and higher efficiency. LEDs find applications in devices like phones and cameras.
This presentation gives a lot of information about
Semiconductor Devices.This is presented by Rajesh Kumar Sangani from Rajiv Gandhi University of Knowledge Technologies,Basar Dist
Adilabad,A.P,India.
02-Fundamentals of Optical Fiber Waveguides-I.pptxAkliluAyele3
This document discusses fundamentals of optical fiber waveguides. It covers topics such as total internal reflection, acceptance angle, numerical aperture, fiber structures, and propagation of light in fibers. A typical optical fiber consists of a core made of glass or plastic, a cladding, and a protective coating. Total internal reflection guides light through the core due to the refractive index difference between the core and cladding. The acceptance angle and numerical aperture characterize a fiber's ability to accept and transmit light.
The document discusses heterojunctions and p-n junctions. It defines a heterojunction as the interface between two dissimilar semiconductors with different band gaps. There are three types of heterojunctions based on band alignment: type I where bands straddle, type II where bands are staggered, and type III where there is a broken gap. A p-n heterojunction diode forms when a p-doped and n-doped semiconductor meet; electrons flow from the higher to lower Fermi level side and holes in the opposite direction.
This document provides a comprehensive presentation on photo detectors. It begins with an outline of topics to be covered, including the history of photo detectors and classifications of optoelectronic semiconductor devices. It then discusses the principles of photo detection, modes of operation for optical detectors, and laws of conservation and optical absorption. Finally, it describes types of photo detectors with respect to PN junctions, including photo diodes, PIN photo diodes, and avalanche photo diodes. Diagrams and equations are provided to illustrate key concepts.
Introduction to Semiconductor Devices.
In modern world no other technology permeates every nook and cranny of our existence as does electronics.
Application of electronics are : Televisions, radios, stereo equipment, computers, scanners, electronic control systems (in cars for example) etc.
The document discusses the Hall effect and its discovery in 1879 by Edwin Hall. It describes how the Lorentz force causes charge accumulation and Hall voltage in conductors placed in magnetic fields. The Hall effect can be used to determine properties of semiconductors like charge carrier density, mobility, and energy gap. A new automated experimental setup using LabVIEW was created to more reliably measure Hall voltage, temperature, and magnetic field, though it had some limitations. Results from measurements on a semiconductor were presented.
This document outlines the principles, characteristics, types, noise, response time, merits, demerits, and applications of photodiodes. It discusses p-i-n photodiodes, avalanche photodiodes (APDs), and InGaAs APDs. P-i-n photodiodes operate based on the photoelectric effect and separation of photogenerated carriers by the reverse bias. APDs multiply the primary photocurrent through impact ionization. Both device types are used in optical communication systems and detectors, while APDs see additional use in applications requiring gain like laser range finders. Noise sources include quantum and dark current noise, and response time depends on carrier transit and diffusion times.
B.tech sem i engineering physics u ii chapter 1-band theory of solidRai University
This document provides an overview of band theory of solids. It discusses effective mass of electrons in solids, the concept of holes, and the energy band structure of conductors, semiconductors, and insulators. Intrinsic and extrinsic semiconductors are described, along with p-type and n-type materials. Simple diode and Zener diode operation is summarized, including forward and reverse bias conditions.
The document discusses the PIN photodiode, including its construction, working, advantages, disadvantages, and applications. A PIN photodiode consists of a p-type semiconductor, intrinsic semiconductor, and n-type semiconductor layer. When light hits the photodiode, electron-hole pairs are generated in the intrinsic region. Under reverse bias, the electrons and holes move to the n-region and p-region respectively, generating an electric current proportional to the light intensity. PIN photodiodes have advantages like wide bandwidth, high speed, and low capacitance compared to PN junction photodiodes. They are used in applications such as optical communications, medical equipment, and light detection.
The document discusses photodetectors and the principles of p-n junction photodiodes. It describes the depletion region of a reverse biased p-n junction and how electron-hole pairs generated by photons are separated by the electric field. It also discusses pin photodiodes and how their intrinsic region allows for higher quantum efficiency and modulation frequencies compared to p-n junction photodiodes. Absorption coefficients of various semiconductor materials are shown as well as how direct and indirect bandgap materials differ in photon absorption.
HALL effect - SemiConductors - and it's Applications - Engineering PhysicsTheerumalai Ga
A 20 mins discussion on the "HALL EFFECT and it's applications" of Semiconductors and a brief explanation about Hall Sensors with a derivation and video attached. Engineering Physics - important area of discussion for Anna University examination- seminar
This presentation covered most of topics related to the superconductor like properties of superconductors, the meissner effect, type 1 and type 2 superconductors their properties and diagram difference between type 1 and type 2 superconductors, Penetration depth,Josephson effect and it's applications, BCS theory, cooper pairs, flux quantization, Effect of current etc...
UV spectroscopy involves promoting electrons from the ground state to excited states of molecules using ultraviolet radiation between 200-400 nm. The absorption of this radiation can be quantified using Beer's law and plotted in an absorption spectrum showing the wavelength of maximum absorption (λmax) and intensity (εmax). Chromophores are functional groups that absorb UV radiation, while auxochromes modify the absorption by inducing bathochromic, hypsochromic, hyperchromic, or hypochromic shifts.
This document provides an overview of photodiode detectors. It discusses the background concepts of p-n photodiodes and their photoconductive and photovoltaic modes of operation. It also covers p-i-n photodiode structures, responsivity and bandwidth characteristics, and noise in photodetectors. Key points include the generation of electron-hole pairs through absorption of photons, drift and diffusion currents, dependence of short-circuit current and open-circuit voltage on light intensity, and the basic circuitry and load lines for photoconductive and photovoltaic modes of a photodiode.
This document discusses semiconductors and their properties. Semiconductors have resistivity between good conductors and insulators, around 10-2 to 104 ohm meters at room temperature. In semiconductors, there is a small forbidden gap between the valence band and conduction band of around 0.7-1.1 electronvolts. This small gap means electrons can move between bands with only a small amount of energy, allowing semiconductors to conduct electricity. In contrast, insulators have a large forbidden gap over 3 electronvolts, while conductors have no gap between bands.
This document discusses surface enhanced Raman spectroscopy (SERS) and the mechanisms that lead to signal enhancement. It explains that SERS combines Raman spectroscopy with localized surface plasmon resonance on metallic nanostructures to amplify the weak Raman signal from molecules up to 1011 times. This electromagnetic enhancement is due to the localized electric fields that excite incident photons and enhance molecular emission. Hotspots between nanoparticle gaps produce particularly large field enhancements. The document outlines excitation rate enhancement, emission rate enhancement, and overall SERS enhancement factor calculations.
This document provides information about diffusion and drift currents. It includes the topic, which is diffusion and drift currents. It also lists the degree, which is a BS(Hons) in Physics from the University of Education Township in Lahore. Finally, it provides references for additional reading on the topics of solid state physics, concepts of modern physics, solid state electronic devices, and the differences between diffusion current and drift current.
Introduction to nanoparticles and bionanomaterialsShreyaBhatt23
what is a nanoparticle, why small is good,nanoscale effect, how to make nanostructures,top down and bottom up approachs,
methods of making nanomaterials,chemical methods od making nanomaterial,bionanomaterials,
Basically i have tried giving every details about the phenomenon Superconductivity in the simplest way. This is my first upload.I'll be very glad if u all give your valuable feedback. Thank u.
X-ray photoelectron spectroscopy (XPS) is a surface-sensitive technique that uses X-rays to eject electrons from a material's surface and measure their kinetic energy to determine the elemental composition and chemical states. Kai Siegbahn developed XPS in the 1950s and won the Nobel Prize for his work. A study used XPS to analyze the surface chemistry of langasite crystals before and after vacuum annealing, finding that higher-temperature annealing reduced the surface concentration of gallium. XPS provides quantitative and chemical state information from the top 10-100 Angstroms of a surface.
This document discusses metal-semiconductor contacts, including Schottky and ohmic contacts. It provides energy band diagrams to illustrate how Schottky and ohmic junctions work. Schottky contacts form a rectifying barrier between a metal and lightly doped semiconductor. Ohmic contacts have a low resistance non-rectifying junction between metal and heavily doped semiconductor. The document discusses the advantages of Schottky diodes for applications such as RF mixing and solar cells due to their higher current and frequency performance compared to PN junction diodes. Ohmic contacts are used where low resistance contact is needed to allow easy flow of charge carriers.
02-Fundamentals of Optical Fiber Waveguides-I.pptxAkliluAyele3
This document discusses fundamentals of optical fiber waveguides. It covers topics such as total internal reflection, acceptance angle, numerical aperture, fiber structures, and propagation of light in fibers. A typical optical fiber consists of a core made of glass or plastic, a cladding, and a protective coating. Total internal reflection guides light through the core due to the refractive index difference between the core and cladding. The acceptance angle and numerical aperture characterize a fiber's ability to accept and transmit light.
The document discusses heterojunctions and p-n junctions. It defines a heterojunction as the interface between two dissimilar semiconductors with different band gaps. There are three types of heterojunctions based on band alignment: type I where bands straddle, type II where bands are staggered, and type III where there is a broken gap. A p-n heterojunction diode forms when a p-doped and n-doped semiconductor meet; electrons flow from the higher to lower Fermi level side and holes in the opposite direction.
This document provides a comprehensive presentation on photo detectors. It begins with an outline of topics to be covered, including the history of photo detectors and classifications of optoelectronic semiconductor devices. It then discusses the principles of photo detection, modes of operation for optical detectors, and laws of conservation and optical absorption. Finally, it describes types of photo detectors with respect to PN junctions, including photo diodes, PIN photo diodes, and avalanche photo diodes. Diagrams and equations are provided to illustrate key concepts.
Introduction to Semiconductor Devices.
In modern world no other technology permeates every nook and cranny of our existence as does electronics.
Application of electronics are : Televisions, radios, stereo equipment, computers, scanners, electronic control systems (in cars for example) etc.
The document discusses the Hall effect and its discovery in 1879 by Edwin Hall. It describes how the Lorentz force causes charge accumulation and Hall voltage in conductors placed in magnetic fields. The Hall effect can be used to determine properties of semiconductors like charge carrier density, mobility, and energy gap. A new automated experimental setup using LabVIEW was created to more reliably measure Hall voltage, temperature, and magnetic field, though it had some limitations. Results from measurements on a semiconductor were presented.
This document outlines the principles, characteristics, types, noise, response time, merits, demerits, and applications of photodiodes. It discusses p-i-n photodiodes, avalanche photodiodes (APDs), and InGaAs APDs. P-i-n photodiodes operate based on the photoelectric effect and separation of photogenerated carriers by the reverse bias. APDs multiply the primary photocurrent through impact ionization. Both device types are used in optical communication systems and detectors, while APDs see additional use in applications requiring gain like laser range finders. Noise sources include quantum and dark current noise, and response time depends on carrier transit and diffusion times.
B.tech sem i engineering physics u ii chapter 1-band theory of solidRai University
This document provides an overview of band theory of solids. It discusses effective mass of electrons in solids, the concept of holes, and the energy band structure of conductors, semiconductors, and insulators. Intrinsic and extrinsic semiconductors are described, along with p-type and n-type materials. Simple diode and Zener diode operation is summarized, including forward and reverse bias conditions.
The document discusses the PIN photodiode, including its construction, working, advantages, disadvantages, and applications. A PIN photodiode consists of a p-type semiconductor, intrinsic semiconductor, and n-type semiconductor layer. When light hits the photodiode, electron-hole pairs are generated in the intrinsic region. Under reverse bias, the electrons and holes move to the n-region and p-region respectively, generating an electric current proportional to the light intensity. PIN photodiodes have advantages like wide bandwidth, high speed, and low capacitance compared to PN junction photodiodes. They are used in applications such as optical communications, medical equipment, and light detection.
The document discusses photodetectors and the principles of p-n junction photodiodes. It describes the depletion region of a reverse biased p-n junction and how electron-hole pairs generated by photons are separated by the electric field. It also discusses pin photodiodes and how their intrinsic region allows for higher quantum efficiency and modulation frequencies compared to p-n junction photodiodes. Absorption coefficients of various semiconductor materials are shown as well as how direct and indirect bandgap materials differ in photon absorption.
HALL effect - SemiConductors - and it's Applications - Engineering PhysicsTheerumalai Ga
A 20 mins discussion on the "HALL EFFECT and it's applications" of Semiconductors and a brief explanation about Hall Sensors with a derivation and video attached. Engineering Physics - important area of discussion for Anna University examination- seminar
This presentation covered most of topics related to the superconductor like properties of superconductors, the meissner effect, type 1 and type 2 superconductors their properties and diagram difference between type 1 and type 2 superconductors, Penetration depth,Josephson effect and it's applications, BCS theory, cooper pairs, flux quantization, Effect of current etc...
UV spectroscopy involves promoting electrons from the ground state to excited states of molecules using ultraviolet radiation between 200-400 nm. The absorption of this radiation can be quantified using Beer's law and plotted in an absorption spectrum showing the wavelength of maximum absorption (λmax) and intensity (εmax). Chromophores are functional groups that absorb UV radiation, while auxochromes modify the absorption by inducing bathochromic, hypsochromic, hyperchromic, or hypochromic shifts.
This document provides an overview of photodiode detectors. It discusses the background concepts of p-n photodiodes and their photoconductive and photovoltaic modes of operation. It also covers p-i-n photodiode structures, responsivity and bandwidth characteristics, and noise in photodetectors. Key points include the generation of electron-hole pairs through absorption of photons, drift and diffusion currents, dependence of short-circuit current and open-circuit voltage on light intensity, and the basic circuitry and load lines for photoconductive and photovoltaic modes of a photodiode.
This document discusses semiconductors and their properties. Semiconductors have resistivity between good conductors and insulators, around 10-2 to 104 ohm meters at room temperature. In semiconductors, there is a small forbidden gap between the valence band and conduction band of around 0.7-1.1 electronvolts. This small gap means electrons can move between bands with only a small amount of energy, allowing semiconductors to conduct electricity. In contrast, insulators have a large forbidden gap over 3 electronvolts, while conductors have no gap between bands.
This document discusses surface enhanced Raman spectroscopy (SERS) and the mechanisms that lead to signal enhancement. It explains that SERS combines Raman spectroscopy with localized surface plasmon resonance on metallic nanostructures to amplify the weak Raman signal from molecules up to 1011 times. This electromagnetic enhancement is due to the localized electric fields that excite incident photons and enhance molecular emission. Hotspots between nanoparticle gaps produce particularly large field enhancements. The document outlines excitation rate enhancement, emission rate enhancement, and overall SERS enhancement factor calculations.
This document provides information about diffusion and drift currents. It includes the topic, which is diffusion and drift currents. It also lists the degree, which is a BS(Hons) in Physics from the University of Education Township in Lahore. Finally, it provides references for additional reading on the topics of solid state physics, concepts of modern physics, solid state electronic devices, and the differences between diffusion current and drift current.
Introduction to nanoparticles and bionanomaterialsShreyaBhatt23
what is a nanoparticle, why small is good,nanoscale effect, how to make nanostructures,top down and bottom up approachs,
methods of making nanomaterials,chemical methods od making nanomaterial,bionanomaterials,
Basically i have tried giving every details about the phenomenon Superconductivity in the simplest way. This is my first upload.I'll be very glad if u all give your valuable feedback. Thank u.
X-ray photoelectron spectroscopy (XPS) is a surface-sensitive technique that uses X-rays to eject electrons from a material's surface and measure their kinetic energy to determine the elemental composition and chemical states. Kai Siegbahn developed XPS in the 1950s and won the Nobel Prize for his work. A study used XPS to analyze the surface chemistry of langasite crystals before and after vacuum annealing, finding that higher-temperature annealing reduced the surface concentration of gallium. XPS provides quantitative and chemical state information from the top 10-100 Angstroms of a surface.
This document discusses metal-semiconductor contacts, including Schottky and ohmic contacts. It provides energy band diagrams to illustrate how Schottky and ohmic junctions work. Schottky contacts form a rectifying barrier between a metal and lightly doped semiconductor. Ohmic contacts have a low resistance non-rectifying junction between metal and heavily doped semiconductor. The document discusses the advantages of Schottky diodes for applications such as RF mixing and solar cells due to their higher current and frequency performance compared to PN junction diodes. Ohmic contacts are used where low resistance contact is needed to allow easy flow of charge carriers.
Teori ekspresivisme memandang karya sastra sebagai ekspresi dunia batin pengarang. Karya sastra dipandang sebagai sarana pengungkap ide, angan-angan, cita-cita, dan pengalaman pengarang. Teori ini mendapat perhatian pada zaman Romantik dengan penekanan pada spontanitas perasaan pengarang dalam karya sastra. Kritik ekspresif berfokus pada kesungguhan, keaslian, dan kemampuan kary
1. The document provides safety instructions for installing, operating, and maintaining bucket elevators and conveyors, noting it is the responsibility of various parties to ensure compliance with relevant safety standards and laws.
2. It lists 14 minimum provisions for safe installation and operation, including locking out power before any maintenance or clearing of jams, and not walking on covers or placing body parts in the conveyor.
3. It emphasizes the importance of locking out power as the only real protection against injury, and warns that secondary safety devices should not replace locking out power when removing guards or covers.