1. The document describes research from University Malaya on improving the efficiency of organic light-emitting diodes (OLEDs) through materials engineering and interfacial design.
2. It discusses techniques developed to increase the efficiency of commercial materials, a methodology for screening molecules computationally, and new emitting host materials synthesized with defined properties for high efficiency.
3. A theoretical framework is presented for understanding organic-organic and inorganic-organic interfaces to achieve low driving voltages in devices. Several patents have also been filed related to OLED project findings.
Suppressing Evanescent Loss in OLEDs Using Low Refractive Index ETLAmin Salehi
SPIE Invited Talk
11:15 am, 6th August 2017.
In this presentation we outline, how using a low refractive index electron transport layer can suppress evanescent loss and increase optical out-coupling.
To cite this presentation please cite this publication:
Salehi A, Ho S, Chen Y, Peng C, Yersin H, So F. Highly Efficient Organic Light‐Emitting Diode Using A Low Refractive Index Electron Transport Layer. Advanced Optical Materials. 2017 Jun 1;5(11).
Spectroscopic Investigation of Laser Treated Nano Material Lead OxideIRJET Journal
This document summarizes a study investigating the effects of laser treatment on lead oxide (PbO) nanoparticles. PbO nanoparticles were synthesized and then treated with either a He-Ne laser or diode laser for varying time durations. The treated and untreated nanoparticles were then characterized using UV-Vis spectroscopy, FTIR spectroscopy, and X-ray diffraction (XRD). UV-Vis analysis showed that laser treatment increased the band gap energy of PbO from 5.3 eV untreated to up to 6.3 eV. FTIR identified the functional groups present. XRD revealed the crystal structure was tetragonal and treatment with the He-Ne laser for 30 minutes produced nanoparticles with the largest average size of 5.0 nm
Synthesis, Ultrasonic Characterization and Comparative Studies of Silver and ...IRJET Journal
1) Gold and silver nanofluids were synthesized using a one-step method involving the reduction of chloroauric acid and silver nitrate with ethylene glycol.
2) The ultrasonic velocity, compressibility, acoustic impedance, and other properties of the nanofluids were calculated at various temperatures using an ultrasonic interferometer.
3) Characterization using techniques like UV-Vis spectroscopy, XRD, and SEM confirmed the formation of gold and silver nanoparticles in the nanofluids. The electrical conductivity of the nanofluids was also measured.
Synthesis, Characterization and Electrical Conductivity Study of Conductive P...IRJET Journal
This document summarizes a study that synthesized polypyrrole doped with nano tin (PPy/Sn) composite for antibacterial applications. PPy and PPy/Sn composite were synthesized via chemical polymerization. Characterization methods included FT-IR, XRD, FESEM-EDX, and electrical conductivity measurements. FT-IR confirmed the presence of nano tin in PPy. XRD showed PPy was amorphous and PPy/Sn was crystalline with average size of 35.68 nm. FESEM images showed uniform distribution of spherical nano tin particles in PPy. Electrical conductivity of PPy/Sn was higher than PPy due to incorporation of nano tin particles. Antibacterial tests found PPy
Optical Studies of Ni and Fe Doped Tin Oxide Nanoparticles by Co-Precipitatio...IRJET Journal
This document describes a study on the synthesis and characterization of pure, nickel-doped, and iron-doped tin oxide nanoparticles. The nanoparticles were synthesized via a co-precipitation method and analyzed using various techniques. X-ray diffraction analysis showed that the nanoparticles crystallized in the tetragonal rutile structure. UV-visible spectroscopy revealed that doping reduced the optical band gap. Fourier transform infrared spectroscopy confirmed the incorporation of nickel and iron into the tin lattice. Photoluminescence spectra exhibited blue emission peaks attributed to electron transitions involving defect levels. Scanning electron microscopy images displayed nanoparticle morphology and energy-dispersive X-ray spectroscopy confirmed the presence of tin, oxygen, and dopants in the samples.
Synthesis, Growth and Optical Properties of L-Threoninium Chloride for Opto e...IRJET Journal
The document summarizes research into synthesizing and characterizing the L-threoninium chloride crystal for optoelectronic applications. Key points:
1. L-threoninium chloride was synthesized via a slow evaporation method from an aqueous solution of L-threonine and hydrochloric acid.
2. The crystal was characterized through X-ray diffraction, FTIR, UV-Vis-NIR, and SHG efficiency measurements.
3. Results showed the crystal has a transmission window of 235-1100nm, is 50% as efficient as KDP for SHG, and is a promising material for optoelectronics.
Synthesis, Structural and Optical Properties of an Organic Stilbazolium Singl...IRJET Journal
1) A new organic nonlinear optical crystal called 4-(4-hydroxy styryl)-1-methylpyridinium 4-styrene sulfonate (HSSS) was synthesized and grown using the slow solvent evaporation method.
2) Single crystal X-ray diffraction analysis confirmed that HSSS crystallizes in the monoclinic crystal system with space group P21/n.
3) NMR and FT-IR spectral analyses were used to identify the functional groups and confirm the structure of HSSS.
4) Optical absorption spectrum analysis identified n-π* and π-π* transitions and showed the material is transparent from 500-1100nm, making it suitable for nonlinear optical
Suppressing Evanescent Loss in OLEDs Using Low Refractive Index ETLAmin Salehi
SPIE Invited Talk
11:15 am, 6th August 2017.
In this presentation we outline, how using a low refractive index electron transport layer can suppress evanescent loss and increase optical out-coupling.
To cite this presentation please cite this publication:
Salehi A, Ho S, Chen Y, Peng C, Yersin H, So F. Highly Efficient Organic Light‐Emitting Diode Using A Low Refractive Index Electron Transport Layer. Advanced Optical Materials. 2017 Jun 1;5(11).
Spectroscopic Investigation of Laser Treated Nano Material Lead OxideIRJET Journal
This document summarizes a study investigating the effects of laser treatment on lead oxide (PbO) nanoparticles. PbO nanoparticles were synthesized and then treated with either a He-Ne laser or diode laser for varying time durations. The treated and untreated nanoparticles were then characterized using UV-Vis spectroscopy, FTIR spectroscopy, and X-ray diffraction (XRD). UV-Vis analysis showed that laser treatment increased the band gap energy of PbO from 5.3 eV untreated to up to 6.3 eV. FTIR identified the functional groups present. XRD revealed the crystal structure was tetragonal and treatment with the He-Ne laser for 30 minutes produced nanoparticles with the largest average size of 5.0 nm
Synthesis, Ultrasonic Characterization and Comparative Studies of Silver and ...IRJET Journal
1) Gold and silver nanofluids were synthesized using a one-step method involving the reduction of chloroauric acid and silver nitrate with ethylene glycol.
2) The ultrasonic velocity, compressibility, acoustic impedance, and other properties of the nanofluids were calculated at various temperatures using an ultrasonic interferometer.
3) Characterization using techniques like UV-Vis spectroscopy, XRD, and SEM confirmed the formation of gold and silver nanoparticles in the nanofluids. The electrical conductivity of the nanofluids was also measured.
Synthesis, Characterization and Electrical Conductivity Study of Conductive P...IRJET Journal
This document summarizes a study that synthesized polypyrrole doped with nano tin (PPy/Sn) composite for antibacterial applications. PPy and PPy/Sn composite were synthesized via chemical polymerization. Characterization methods included FT-IR, XRD, FESEM-EDX, and electrical conductivity measurements. FT-IR confirmed the presence of nano tin in PPy. XRD showed PPy was amorphous and PPy/Sn was crystalline with average size of 35.68 nm. FESEM images showed uniform distribution of spherical nano tin particles in PPy. Electrical conductivity of PPy/Sn was higher than PPy due to incorporation of nano tin particles. Antibacterial tests found PPy
Optical Studies of Ni and Fe Doped Tin Oxide Nanoparticles by Co-Precipitatio...IRJET Journal
This document describes a study on the synthesis and characterization of pure, nickel-doped, and iron-doped tin oxide nanoparticles. The nanoparticles were synthesized via a co-precipitation method and analyzed using various techniques. X-ray diffraction analysis showed that the nanoparticles crystallized in the tetragonal rutile structure. UV-visible spectroscopy revealed that doping reduced the optical band gap. Fourier transform infrared spectroscopy confirmed the incorporation of nickel and iron into the tin lattice. Photoluminescence spectra exhibited blue emission peaks attributed to electron transitions involving defect levels. Scanning electron microscopy images displayed nanoparticle morphology and energy-dispersive X-ray spectroscopy confirmed the presence of tin, oxygen, and dopants in the samples.
Synthesis, Growth and Optical Properties of L-Threoninium Chloride for Opto e...IRJET Journal
The document summarizes research into synthesizing and characterizing the L-threoninium chloride crystal for optoelectronic applications. Key points:
1. L-threoninium chloride was synthesized via a slow evaporation method from an aqueous solution of L-threonine and hydrochloric acid.
2. The crystal was characterized through X-ray diffraction, FTIR, UV-Vis-NIR, and SHG efficiency measurements.
3. Results showed the crystal has a transmission window of 235-1100nm, is 50% as efficient as KDP for SHG, and is a promising material for optoelectronics.
Synthesis, Structural and Optical Properties of an Organic Stilbazolium Singl...IRJET Journal
1) A new organic nonlinear optical crystal called 4-(4-hydroxy styryl)-1-methylpyridinium 4-styrene sulfonate (HSSS) was synthesized and grown using the slow solvent evaporation method.
2) Single crystal X-ray diffraction analysis confirmed that HSSS crystallizes in the monoclinic crystal system with space group P21/n.
3) NMR and FT-IR spectral analyses were used to identify the functional groups and confirm the structure of HSSS.
4) Optical absorption spectrum analysis identified n-π* and π-π* transitions and showed the material is transparent from 500-1100nm, making it suitable for nonlinear optical
Linear and Nonlinear Optical Properties of Metal Incorporated L-Serine CrystalIRJET Journal
1. L-Serine Potassium Carbonate (LSPC), a metal-incorporated amino acid crystal, was grown using the slow evaporation method.
2. The optical properties of LSPC were studied, including a band gap of 6.33 eV determined from absorption data.
3. LSPC showed good linear optical properties such as low reflectance and refractive index, making it suitable for applications like antireflection coatings. It also exhibited high second harmonic generation efficiency.
Inkjet printed graphene-based flexible humidity sensor for environmental appl...Conference Papers
This document summarizes research on an inkjet-printed graphene-based flexible humidity sensor. Key points:
- Researchers from MIMOS Berhad developed a humidity sensor consisting of an interdigitated electrode made from reduced graphene oxide and silver nanoparticle ink, with graphene oxide as the sensing material, printed on a flexible polyethylene terephthalate substrate.
- The graphene oxide sensing material's dielectric constant changes with humidity, allowing the sensor to detect humidity levels based on capacitance measurements.
- Testing showed the sensor achieved a highest sensitivity of 0.15pF/%RH at 50°C, with a linear response at low humidity and exponential increase above 60%RH. It also demonstrated good temperature dependence below
This curriculum vitae is for Prateek Khare, who was born in 1984 in India. He received a Ph.D in Chemical Engineering from IIT Kanpur in 2016, an M.Tech from NIT Rourkela in 2011, and a B.Tech from CSJMU Kanpur in 2009. He has filed two patents and has published 10 papers in various journals on topics related to environmental remediation and materials science. He has also presented research at two conferences in India.
The document studies the effect of varying doping concentrations of C545T in an Alq3 host on the performance of fluorescent organic light-emitting diodes. It finds that higher doping concentrations, up to 4%, improve charge balance through direct charge trapping of holes and electrons at the dopant sites. The optimal doping concentration of 4% achieves a high current efficiency of 12.5 cd/A across a wide range of luminance levels by balancing exciton formation through energy transfer and direct charge recombination.
FTIR, Electrical and SHG Studies of Single Crystals of KDP Doped With Phenyla...iosrjce
IOSR Journal of Applied Physics (IOSR-JAP) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of physics and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in applied physics. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
This document summarizes research on using nanostructured electromaterials for energy applications. It discusses using precision assembly of nano- and micro-dimensional components into macroscopic structures to improve device performance. Specific examples discussed include using porphyrins, conducting polymers, and graphene in dye-sensitized solar cells, hydrogen production, and nanostructure fabrication. The goal is to create the next generation of electrochemical devices through 3D assembly of electromaterials at the nano- and micro-scale.
International Journal of Engineering Research and DevelopmentIJERD Editor
Electrical, Electronics and Computer Engineering,
Information Engineering and Technology,
Mechanical, Industrial and Manufacturing Engineering,
Automation and Mechatronics Engineering,
Material and Chemical Engineering,
Civil and Architecture Engineering,
Biotechnology and Bio Engineering,
Environmental Engineering,
Petroleum and Mining Engineering,
Marine and Agriculture engineering,
Aerospace Engineering.
Growth, structural and optical studies of pure and kbr doped adp crystalseSAT Journals
Abstract Pure and KBr doped crystals of ADP were grown by slow evaporation technique from the supersaturated solution of ADP at room temperature. The tetragonal structure of the grown crystals was observed by powder X-ray diffraction analysis. FTIR spectra revealed the presence of functional groups present in the grown crystals. The UV-Vis spectral analysis shows high transparency in the entire visible region. The band gap value of the pure ADP crystal was found assuming indirect transition. Key Words: ADP, Powder XRD, FTIR, Band gap
En estas diapositivas podrán encontrar todo lo relacionado con los alimento y que los con lleva a la química y también todo lo relacionado y lo mas importante de los conservadores
This document provides guidance on how to conduct research effectively. It discusses important considerations when starting a research project such as defining a clear research question, gathering relevant information through reading, and formulating testable hypotheses. The document also outlines key steps in the scientific process including designing experiments, collecting and analyzing data, and drawing conclusions. Additionally, it offers advice on how to approach challenges in research such as exposing assumptions, investigating anomalies, and developing necessary tools to make progress on solving research problems.
Las frutas son ricos en vitaminas, minerales y agua, y bajos en calorías. Están compuestos principalmente de agua, carbohidratos, fibra, vitaminas y sales minerales. Las frutas se clasifican de diferentes maneras, incluyendo por su textura (frutos secos o carnosos), tiempo de consumo (fresca o seca), y tipo de maduración (climatérica o no climatérica).
Los ésteres se forman por la reacción entre un ácido y un alcohol, con pérdida de agua. Se usan como plastificantes, aromas artificiales, aditivos alimentarios, productos farmacéuticos y repelentes de insectos. Tienen propiedades físicas como ser líquidos de olor agradable o sólidos cristalinos, e hidrolizan en presencia de agua para regenerar el ácido y el alcohol originales.
El documento describe la historia, propiedades, métodos de obtención y aplicaciones del etanol. Explica que el etanol se puede obtener por fermentación de azúcares o por síntesis química de etileno, y que tiene usos en bebidas, combustibles y productos industriales. También analiza las ventajas de su uso como biocombustible y las limitaciones ambientales de su producción.
Este documento describe los ésteres, incluyendo su nomenclatura, propiedades, reacciones y usos. Los ésteres son compuestos formados por la sustitución del hidrógeno de un ácido orgánico por una cadena hidrocarbonada. Se utilizan ampliamente en perfumes, sabores y solventes debido a sus olores distintivos. Algunos ésteres también tienen aplicaciones médicas importantes como la aspirina.
Los ésteres se forman por la reacción entre un ácido y un alcohol. Se nombran reemplazando la terminación del ácido con "oato" y el nombre del radical del alcohol. Tienen propiedades como ser solubles en solventes orgánicos e insolubles en agua. Pueden hidrolizarse en presencia de un catalizador ácido para formar el ácido y alcohol originales.
Este documento describe los factores que afectan la calidad de las frutas y hortalizas. Explica que la calidad se ve afectada por factores precosecha como la variedad genética, el suelo y el clima, y por factores postcosecha como el estado de madurez durante la recolección, la conservación, los tratamientos tecnológicos y la transformación culinaria. Además, analiza cómo procesos como la respiración y la pérdida de agua afectan la calidad durante la postcosecha.
Los éteres tienen la estructura general R-O-R, con un átomo de oxígeno unido a dos grupos hidrocarburos. Los éteres más comunes son el éter dietílico y el tetrahidrofurano. Los ésteres tienen la estructura R-C(=O)-O-R y se forman por la reacción de condensación entre un ácido carboxílico y un alcohol. Los ésteres más utilizados son los ésteres de acetato como el acetato de etilo. Tanto los éteres como los ésteres sufren hidró
Plenary lecture of the XIII SBPMat (Brazilian MRS) meeting, given on September 30th 2014 by Karl Leo, professor of optoelectronics at Dresden University of Technology (Germany) and director of the Solar and Photovoltaic Engineering Research Center at KAUST (Saudi Arabia).
IRJET - Review on Ameliorated in the Life, and Calibrated the OledIRJET Journal
This document summarizes research on improving the lifespan of OLED (organic light-emitting diode) displays. It discusses how OLED degradation occurs through chemical breakdown processes involving radical species. Methods to improve OLED lifetime are proposed, including using thermally activated delayed fluorescent materials and adding a thin lithium-containing layer. The document also reviews the structure and functioning of OLEDs, different degradation mechanisms, and potential future applications and challenges of OLED technology.
This document summarizes research on the effect of different organic solvents and annealing temperatures on the optical properties of TiO2 nanoparticles. Specifically, it finds that using benzyl alcohol as the solvent instead of ethanol results in larger particle sizes of 40-60 nm compared to 20-30 nm. This is because benzyl alcohol has a higher boiling point, allowing more time for nucleation and growth. The larger particles have a lower band gap, absorbing visible light up to 400 nm instead of 350 nm. Overall, the solvent's boiling point influences particle size, which then affects the optical properties of the TiO2 nanoparticles.
This document discusses transparent electronics. Transparent electronics are materials that are both optically transparent and electrically conductive. Common transparent conducting oxides used include indium oxide, zinc oxide, and cadmium oxide. These materials can be fabricated using methods like sputtering, vacuum evaporation, chemical vapor deposition, and pulsed laser deposition. The document describes applications for transparent electronics such as transparent thin film transistors, UV detectors, and OLED displays. Advantages include flexibility and reduced costs, while disadvantages include shorter lifetimes and higher manufacturing costs compared to traditional electronics.
Linear and Nonlinear Optical Properties of Metal Incorporated L-Serine CrystalIRJET Journal
1. L-Serine Potassium Carbonate (LSPC), a metal-incorporated amino acid crystal, was grown using the slow evaporation method.
2. The optical properties of LSPC were studied, including a band gap of 6.33 eV determined from absorption data.
3. LSPC showed good linear optical properties such as low reflectance and refractive index, making it suitable for applications like antireflection coatings. It also exhibited high second harmonic generation efficiency.
Inkjet printed graphene-based flexible humidity sensor for environmental appl...Conference Papers
This document summarizes research on an inkjet-printed graphene-based flexible humidity sensor. Key points:
- Researchers from MIMOS Berhad developed a humidity sensor consisting of an interdigitated electrode made from reduced graphene oxide and silver nanoparticle ink, with graphene oxide as the sensing material, printed on a flexible polyethylene terephthalate substrate.
- The graphene oxide sensing material's dielectric constant changes with humidity, allowing the sensor to detect humidity levels based on capacitance measurements.
- Testing showed the sensor achieved a highest sensitivity of 0.15pF/%RH at 50°C, with a linear response at low humidity and exponential increase above 60%RH. It also demonstrated good temperature dependence below
This curriculum vitae is for Prateek Khare, who was born in 1984 in India. He received a Ph.D in Chemical Engineering from IIT Kanpur in 2016, an M.Tech from NIT Rourkela in 2011, and a B.Tech from CSJMU Kanpur in 2009. He has filed two patents and has published 10 papers in various journals on topics related to environmental remediation and materials science. He has also presented research at two conferences in India.
The document studies the effect of varying doping concentrations of C545T in an Alq3 host on the performance of fluorescent organic light-emitting diodes. It finds that higher doping concentrations, up to 4%, improve charge balance through direct charge trapping of holes and electrons at the dopant sites. The optimal doping concentration of 4% achieves a high current efficiency of 12.5 cd/A across a wide range of luminance levels by balancing exciton formation through energy transfer and direct charge recombination.
FTIR, Electrical and SHG Studies of Single Crystals of KDP Doped With Phenyla...iosrjce
IOSR Journal of Applied Physics (IOSR-JAP) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of physics and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in applied physics. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
This document summarizes research on using nanostructured electromaterials for energy applications. It discusses using precision assembly of nano- and micro-dimensional components into macroscopic structures to improve device performance. Specific examples discussed include using porphyrins, conducting polymers, and graphene in dye-sensitized solar cells, hydrogen production, and nanostructure fabrication. The goal is to create the next generation of electrochemical devices through 3D assembly of electromaterials at the nano- and micro-scale.
International Journal of Engineering Research and DevelopmentIJERD Editor
Electrical, Electronics and Computer Engineering,
Information Engineering and Technology,
Mechanical, Industrial and Manufacturing Engineering,
Automation and Mechatronics Engineering,
Material and Chemical Engineering,
Civil and Architecture Engineering,
Biotechnology and Bio Engineering,
Environmental Engineering,
Petroleum and Mining Engineering,
Marine and Agriculture engineering,
Aerospace Engineering.
Growth, structural and optical studies of pure and kbr doped adp crystalseSAT Journals
Abstract Pure and KBr doped crystals of ADP were grown by slow evaporation technique from the supersaturated solution of ADP at room temperature. The tetragonal structure of the grown crystals was observed by powder X-ray diffraction analysis. FTIR spectra revealed the presence of functional groups present in the grown crystals. The UV-Vis spectral analysis shows high transparency in the entire visible region. The band gap value of the pure ADP crystal was found assuming indirect transition. Key Words: ADP, Powder XRD, FTIR, Band gap
En estas diapositivas podrán encontrar todo lo relacionado con los alimento y que los con lleva a la química y también todo lo relacionado y lo mas importante de los conservadores
This document provides guidance on how to conduct research effectively. It discusses important considerations when starting a research project such as defining a clear research question, gathering relevant information through reading, and formulating testable hypotheses. The document also outlines key steps in the scientific process including designing experiments, collecting and analyzing data, and drawing conclusions. Additionally, it offers advice on how to approach challenges in research such as exposing assumptions, investigating anomalies, and developing necessary tools to make progress on solving research problems.
Las frutas son ricos en vitaminas, minerales y agua, y bajos en calorías. Están compuestos principalmente de agua, carbohidratos, fibra, vitaminas y sales minerales. Las frutas se clasifican de diferentes maneras, incluyendo por su textura (frutos secos o carnosos), tiempo de consumo (fresca o seca), y tipo de maduración (climatérica o no climatérica).
Los ésteres se forman por la reacción entre un ácido y un alcohol, con pérdida de agua. Se usan como plastificantes, aromas artificiales, aditivos alimentarios, productos farmacéuticos y repelentes de insectos. Tienen propiedades físicas como ser líquidos de olor agradable o sólidos cristalinos, e hidrolizan en presencia de agua para regenerar el ácido y el alcohol originales.
El documento describe la historia, propiedades, métodos de obtención y aplicaciones del etanol. Explica que el etanol se puede obtener por fermentación de azúcares o por síntesis química de etileno, y que tiene usos en bebidas, combustibles y productos industriales. También analiza las ventajas de su uso como biocombustible y las limitaciones ambientales de su producción.
Este documento describe los ésteres, incluyendo su nomenclatura, propiedades, reacciones y usos. Los ésteres son compuestos formados por la sustitución del hidrógeno de un ácido orgánico por una cadena hidrocarbonada. Se utilizan ampliamente en perfumes, sabores y solventes debido a sus olores distintivos. Algunos ésteres también tienen aplicaciones médicas importantes como la aspirina.
Los ésteres se forman por la reacción entre un ácido y un alcohol. Se nombran reemplazando la terminación del ácido con "oato" y el nombre del radical del alcohol. Tienen propiedades como ser solubles en solventes orgánicos e insolubles en agua. Pueden hidrolizarse en presencia de un catalizador ácido para formar el ácido y alcohol originales.
Este documento describe los factores que afectan la calidad de las frutas y hortalizas. Explica que la calidad se ve afectada por factores precosecha como la variedad genética, el suelo y el clima, y por factores postcosecha como el estado de madurez durante la recolección, la conservación, los tratamientos tecnológicos y la transformación culinaria. Además, analiza cómo procesos como la respiración y la pérdida de agua afectan la calidad durante la postcosecha.
Los éteres tienen la estructura general R-O-R, con un átomo de oxígeno unido a dos grupos hidrocarburos. Los éteres más comunes son el éter dietílico y el tetrahidrofurano. Los ésteres tienen la estructura R-C(=O)-O-R y se forman por la reacción de condensación entre un ácido carboxílico y un alcohol. Los ésteres más utilizados son los ésteres de acetato como el acetato de etilo. Tanto los éteres como los ésteres sufren hidró
Plenary lecture of the XIII SBPMat (Brazilian MRS) meeting, given on September 30th 2014 by Karl Leo, professor of optoelectronics at Dresden University of Technology (Germany) and director of the Solar and Photovoltaic Engineering Research Center at KAUST (Saudi Arabia).
IRJET - Review on Ameliorated in the Life, and Calibrated the OledIRJET Journal
This document summarizes research on improving the lifespan of OLED (organic light-emitting diode) displays. It discusses how OLED degradation occurs through chemical breakdown processes involving radical species. Methods to improve OLED lifetime are proposed, including using thermally activated delayed fluorescent materials and adding a thin lithium-containing layer. The document also reviews the structure and functioning of OLEDs, different degradation mechanisms, and potential future applications and challenges of OLED technology.
This document summarizes research on the effect of different organic solvents and annealing temperatures on the optical properties of TiO2 nanoparticles. Specifically, it finds that using benzyl alcohol as the solvent instead of ethanol results in larger particle sizes of 40-60 nm compared to 20-30 nm. This is because benzyl alcohol has a higher boiling point, allowing more time for nucleation and growth. The larger particles have a lower band gap, absorbing visible light up to 400 nm instead of 350 nm. Overall, the solvent's boiling point influences particle size, which then affects the optical properties of the TiO2 nanoparticles.
This document discusses transparent electronics. Transparent electronics are materials that are both optically transparent and electrically conductive. Common transparent conducting oxides used include indium oxide, zinc oxide, and cadmium oxide. These materials can be fabricated using methods like sputtering, vacuum evaporation, chemical vapor deposition, and pulsed laser deposition. The document describes applications for transparent electronics such as transparent thin film transistors, UV detectors, and OLED displays. Advantages include flexibility and reduced costs, while disadvantages include shorter lifetimes and higher manufacturing costs compared to traditional electronics.
This document discusses transparent electronics. Transparent electronics are materials that are both optically transparent and electrically conductive. Common transparent conducting oxides used include indium oxide, zinc oxide, and cadmium oxide. These materials can be fabricated using methods like sputtering, evaporation, chemical vapor deposition, and pulsed laser deposition. Transparent electronics have applications in devices like transparent thin-film transistors and UV detectors. Additional applications discussed include uses in OLED displays, transparent solar panels, and other domestic, entertainment, communication, architecture, healthcare, and industrial applications.
This document discusses organic light-emitting diodes (OLEDs). It describes the basic structure of OLEDs, which consists of an organic layer sandwiched between an anode and cathode. When voltage is applied, electrons and holes are injected from the electrodes and recombine in the organic layer, emitting light. The document outlines the different layers in OLEDs, including hole injection, hole transport, electron transport, and emissive layers. It notes advantages of OLEDs such as high brightness, contrast, and response time. OLEDs have applications in displays, lighting, and other areas.
This presentation summarizes history and recent development of perovskite solar cells. If you have any questions or comments, you can reach me at agassifeng@gmail.com
The document discusses thermally activated delayed fluorescence (TADF) for organic light emitting diodes. It begins with an introduction to TADF and the mechanisms allowing conversion of triplet excitons to light. Key parameters for efficient TADF emitters include a small singlet-triplet energy gap, high photoluminescence quantum yield, and high oscillator strength. Molecular design strategies aim to engineer these parameters, such as introducing strong donor-acceptor motifs or using spiro linkers to separate orbitals. The document concludes that TADF could harvest normally wasted triplet excitons, improving light emission efficiency.
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.
Natural Dye-Sensitized Solar Cells (NDSSCs) From Opuntia Prickly Pear Dye Usi...IJERA Editor
Natural dye-sensitized solar cells (NDSSCs) have gained considerable attention in the field of solar energy due to their simple fabrication, good efficiency, and low production cost. Natural dyes are environmentally and economically superior to ruthenium-based dyes because they are nontoxic and cheap. However, the conversion efficiency of dye-sensitized solar cells based on natural dyes is low. One way to improve the DSSC performance is to enhance the absorptivity of extracted natural dyes. We investigated the influence of various factors in the extraction process, such as utilization of different extraction approaches, the acidity of extraction solvent, and different compounds of solvents on the optical absorption spectra. It was found that we could considerably enhance the optical absorptivity of dye and consequently the performance of DSSC by choosing a proper mixture of ethanol, methanol and water. In this study, a photo electrode using ZnO doped TiO2 nanoparticles was prepared by sol-gel method. In this paper we investigate the optical absorption, functional group, surface morphology and elementary composition of pure TiO2, ZnO doped TiO2 nanoparticles and opuntia prickly pear dye extract by using UV-Visible, PL-Studies, FT-IR, FE-SEM and EDS analysis. Finally photocurrent-voltaic characterization of nanocrystaline natural dye solar cell using I-V studies. It was found that the levels of short-circuit current (Jsc), open-circuit voltage (Voc), fill factor (FF) and overall conversion efficiency (η).
Introduction to atomic layer deposition (ALD): principles, applications, futureRiikka Puurunen
<erratum at the bottom / update 3.5.2019> Introductory lecture on Atomic Layer Deposition (ALD) by Prof. Riikka Puurunen, given at Aalto University School of Chemical Engineering on November 8, 2018. Lecture contents: Principles and concepts of ALD; Some history; Applications of ALD; Words on future. In addition to the core lecture contents, discusses where we have ALD layers in our smart mobile phones; mentions (some) faces of ALD in Finland; STG podcasts; Virtual Project on the History of ALD.
Corresponding lecture capture by Panopto available at: https://aalto.cloud.panopto.eu/Panopto/Pages/Viewer.aspx?id=bd0aee67-7ca5-4973-8216-a99200e888b1
Erratum! Small errors spotted in the slides are described below. Updated 3.5.2019.
* slide 44 Luminescent: ZnS:Mg —> not Mg but Mn! --> ZnS:Mn
* slide 54 high-k solution: article not from 2017 but 2007
The document summarizes research on OLED lighting conducted by Prof. Monkman's OEM Research Group. It discusses how OLED lighting offers better design flexibility compared to traditional lighting. However, two major challenges remain: improving light out-coupling from OLEDs and developing better blue emitter materials that are bright and stable enough. The document also examines the temperature dependence of phosphorescence in polymer films like PVK, providing evidence that monomeric and dimeric ground state species exist.
Analysis of Ketoconazole and Piribedil Using Ion Selective ElectrodesIOSR Journals
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- A DSSC was fabricated using a platinum-coated counter electrode, titanium dioxide photoelectrode, iodolyte electrolyte, and a natural dye extracted from unripe mango peels.
- The energy conversion efficiency of the fabricated DSSC was measured to be 0.345%. I-V curves and absorption/transmittance spectra were also determined.
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Under a Compulsory Course of "Materials Physics and Technology for Nanoelectronics" a team of BE Students of Nanotechnology, Nanoelectronics and Bionnotechnology prepared this seminar for Prof. Marc Heyns, marc.heyns@imec.be Kapeldreef 75, B-3001 Heverlee IMEC Building IV, room 2.33
Tel: 016 281 348
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1. University Malaya
Woon Kai Lin1, Yeo Keat Hoe1, Thomas J Whitcher1, Noor Azrina Talik1, Calvin Ng1 ,Wang Seng Wong1
Zainal A. Hasan2, Bee Kian Ong2, Azhar Ariffin2, Show-An Chen3, Raimonda Griniene4, Saulius
Grigalevicius4 ,Narong Chanlek4, Hideki Nakajima5, Thainit Saisopa5, Prayoon Songsiriritthigul5, Yap Boon Kar6
1. Physics Department, University of Malaya
2. Chemistry Department, University of Malaya
3. Chemical Engineering Department, National Tsing Hua University, Taiwan
4. Department of Polymer Chemistry and Technology, Kaunas University of Technology, Lithuania
5. Thailand Synchrotron Light Source, Thailand
6. University Tenaga Nasional, College of Engineering
1
High efficiency Solution Processable Organic Light
Emitting Diode Through Materials and Interfacial
Engineering
3. What is a good organic LED
Stability
(eg outdoor, indoor ,
Portable in/outdoor)
Cost
(cheap
manufacturing,
Initial cost of
investment?)
Efficiency
( lm/W, cd/A)
Functionality
(eg transparency, flexibility
Aesthetic, ease of integration)
OLED
Technology
Product
4. Example of OLED Applications
5
Artistic OLED lighting OLED TV
Identification Security
Flexible OLED for Cloud Computing
Foldable OLED for cloud
computing
Gadget, Internet of
Things, smart watch
Medical OLED lights for
cancer cells killing.
OLED Data Glass
Medical OLED
BMW car light
Internet
Interconnectedness
6. OLED Efficiency
5
Quantum efficiency increased significantly
When efforts are taken to overcome the
1. Light trapped in the substrate
2. Waveguide loss
3. Surface plasmons
etc…
Focus on the device
level only
EQE max ~ 15%
7. OLED Problem Statements
5
• Limited number of ways to increase device
efficiency of existing materials. (Problem A)
• Material synthesis is often done by trials and
errors.(Problem B)
• Limited number of solution processable materials
for the blue host.(Problem C)
8. Proposed Study
5
• Limited number of ways to increase device efficiency of existing
materials.
Study of interfacial Physics. Multilayer OLED by solution process.
• Limited number of solution processable materials for the blue.
Synthesizing new materials
• Material synthesis is often done by trials and errors.
Leverage on increasing computational power. Do simulation
study
10. In the presentation slide,
I will group the level of
technology readiness
from our research group.
Role of university
Role of start-
up and
industry
11. Efficiency enhancement of a solution processed single layer blue
PHOLED using Triton X-100TRL-4
For high efficiency OLED, the host must have
higher triplet energy than the emitter to avoid
energy back transfer.
Triton
X-100
concentr
ation
(wt%)
VON
(1cd/m2
)
1VON
1PE
(lm/W)
1CE
(cd/A)
2VON
2PE
(lm/
W)
2CE
(cd/A)
0 4.6 6.7 3.9 8.4 8.5 4.9 13.4
0.8 4.5 6.4 4.4 9.2 8.2 5.7 14.7
3.2 3.5 5.6 7.0 12.7 7.3 8.5 20.1
10 4.2 5.9 5.7 6.9 7.3 7.6 16.5
Featured as a cover page
1At brightness of 100 cd/m2
2At brightness of 1000 cd /m2
K.H. Yeoh, C.L. Chua, K.L. Woon
Synthetic Metals 172,44 (2013)
12. Multi layer blue phosphorescent OLED
(a)
11 lm/W
(0.16,0.38)
(b)
TRL-4
Keat Hoe Yeoh, Calvin Yi Bin Ng, Chong Lim Chua, Noor
AzrinaTalik, and Kai Lin Woon, Phys. Status Solidi Rapid
Research Letters , 1–4 (2013)
13. Energy Barrier
Thomas Whitcher; Wong Wah Seng; Talik Noor Azrina; Woon Kai
,Chanlek, Narong; Nakajima Hideki; Saisopa Thanit;
Songsiriritthigul Prayoon, J. Phys. D: Appl. Phys. 49 (2016)
325106
TRL-3
Gaussian disorder is a measure of positional
and energy disorder of organic materials.
Crystal has small disorder.
Fermi-pinning is non-existent for all of the
DOS widths simulated if we use polymer
conducting electrodes
Fermi-level pinning is something that occurs at metal-semiconductor interfaces. It creates
an energy barrier for electrons and holes by bending the bands at the interface.It degrades
performance radically in devices because it's a parasitic resistance that burns energy while
doing nothing useful.
Energybarrier
Work Function of electrode
Energybarrier
Decrease barrier
with decreasing
disorder
Work Function of polymeric electrode
ITO
Fermi pinning
Near zero
barrier
Decrease barrier
with decreasing
disorder
High work-
function is
GOOD
14. Energy Level MatchingTRL-4
Blue phosphorescent host often has a deeper HOMO level. By using self-organizing
Nafion doped Pedot:Pss, the work function of PEDOT:PSS can match with the host.
Increase hole
injection
Optimized blue device efficiency (Device III) improves from 7.3
lmW-1 (15.4 cd/A) and 5.9 lmW-1 (16.5 cd/A) to 9.4 lmW-1
(18.2 cd/A) and 7.9 lmW-1 (20.4 cd/A) at 100 cdm-2 and 1000
cdm-2 respectively.
Keat Hoe Yeo,Noor Azrina Talik, Thomas Whitcher, Calvin Ng, Kai Lin Woon
J. Phys. D: Appl. Phys. 47 (2014) 205103
15. Single layer fluorescent yellow OLED
Fluorinatedalcohol
Ethanol
19
TRL-4
Calvin Yi Bin Ng, Keat Hoe Yeoh, , Thomas J. Whitcher, Noor Azrina
Talik , Kai Lin Woon, Thanit Saisopa, Hideki Nakajima, Ratchadaporn
Supruangnet and Prayoon Songsiriritthigul,
Journal of Physics D: Applied Physics 47 205103 (2014)
16. Single layer fluorescent yellow OLED
19
TRL-4
The device with MoO3 shows efficiencies up to
(22.8 ± 2.5) cd/A with (14.3± 1.9) lm/W having
CIE coordinate of (0.48, 0.52).
N.A Talik, K.L Woon, .K Yap, W. S. Wong, T.J.Whitcher, N. Chanlek,H.
Nakajima, T. Saisopa, P. Songsiriritthigul,
Journal of Physics D: Applied Physics (2016) accepted
17. TANDEM OLED
N.A Talik; K.H Yeoh; C.Y.B Ng; B.K. Yap; Kai Lin Woon, Journal of Luminescence, 154,345, (2014)
TRL-3
Tandem OLED is two or more OLEDs
combined into a single unit.
Cd/A also increase. Have been
demonstrated in vacuum process
We are the first group in the world to
demonstrate it in solution process.
Very challenging to make tandem OLEDs
by solution process.
18. High Work function ITOTRL-4
Science 20 May 2011
Inspired by the science paper
ITO
Cl Cl Cl Cl Cl
We are trying to do
ITO
F F F F F
ITO
Spin coat
CsF..bake it and
Wash with water
T. J. Whitcher, K. H. Yeoh, C. L. Chua,
K. L. Woon, N. Chanlek, H. Nakajima,T.
Saisopa,and P.Songsiriritthigul J. Phys.
D: Appl. Phys. 46 (2013) 475102
What we discover, it is not the F, but
the flattening of the surface of ITO
19. The use of grid computing
to pre-screen materials to
be synthesized. To
optimize the energy level
of molecules and triplet
energy.
The need to benchmark
the theory and experiment
=> calibration curve.
27
Computational study
Bee Kian Ong, Kai Lin Woon, Azhar Ariffin Synthetic Metals,195,54 (2014)
TRL-2
20. 27
Computational studyTRL-2
One of important parameters for high triplet energy is short conjugation for blue OLED
High torsional angle between 2 rings
tend to give high triplet energy
38 molecules are studied
N
H
N
N
H
N
N
N
N
N
N
N
N
H
N
N
N
N
N
N
N
N N
DTFT is
performed to
calculate the
triplet energy.
The red
indicated
triplet energy >
2.95eV good
for the blue
21. Engineering High triplet
Materials
K. L. Woon, Z. A. Hasan, B.K.Ong, A. Ariffin, R. Griniene,S. Grigalevicius, Show-An Chen RSC Adv. ,2015, 5 , 59960–59969
TRL-3
In contrast with widespread belief, triplet energy in solid is more important.
Most measurement is done in liquid. The intermolecular distance can influence the triplet
energy.
23. Engineering High triplet
Materials (3rd generation material)
TRL-3
Fluorination induces stability (just like Teflon).
Let look at how fluorination helps in OLED materials
Red-shift the emission. Reduce
bandgap.
Maintain triplet energy except with the
ter-butyl group
Kai Lin Woon, Zakaria Nurul Nadiah, Zainal Abidin Hasan, Azhar Ariffin, Show-An Chen
Dyes and Pigments, 132, 1–6 (2016)
24. Material synthesisTRL-3
0.5g needs to be synthesized for device testing
a) Cu, K2CO3
, 18
-
Crown-
6, 1,2
-
dchlorobenzene, 180o
C
II
I I
I I
I
I
a
a a
a
N
H
N
N
9 (70%)
10 (70%)
12 (70%)
11 (70%)
N
NN
N
N N
N
NN
N
N N
N
NN
N
N N
N
NN
N
N
N
ET =2.71eV ET=2.82eV ET = 2.53eV ET = 2.73eV
Tg =224oC Tg = 270oC Tg =198oC Tg =274oC
26. TRL-4 EXTRA WARM WHITE OLED
Strong-blue emission drastically suppresses the secretion of melatonin (MLT). Increase the risk of breast,
colorectal, and prostate cancers.*
* Pauley S. M., “Lighting for the human circadian clock: recent research indicates that lighting has become a public health issue,” Med. Hypotheses.
63, (4 ), 588 –596 (2004)
Device structure
+ energy level
0.2 0.3 0.4 0.5 0.6 0.7
0.2
0.3
0.4
0.5
0.6
0.7
1000cd/m2
6551cd/m2
y
x
Plankian locus
Device
1cd/m2
0.1 1 10 100 1000 10000
0
2
4
6
8
10
12
14
16
18
20
22
24
26
28
30
32
Brightness (cd/m2
)
CurrentEfficiency(cd/A)
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
PowerEfficiency(lm/W)
400 450 500 550 600 650 700
0.0
0.2
0.4
0.6
0.8
1.0
Intensity(Count(Normalize))
Wavelength (nm)
Performance of
Device
Value
Startup voltage (V) 4.0
Colour
temperature @
1000cdm-2
2500K
Maximum current
efficiency (cd/A)
26.0
Maximum power
efficiency (lm/W)
13.6
CIE Coordinate
when 1000cd/m2
(0.4832,
0.4273)
27. Conclusions
1. We have developed various techniques for improving the device
efficiency with commercial available materials.
2. We have developed a methodology to screen large amount of
molecules.
3. We have synthesized light emitting host and defined new
material requirement for high efficiency organic LED.
4. We have built a theoretical framework for the organic-organic
and inorganic-organic interfaces for low driving voltage devices.
28. Patent Filed under OLED project
1. Organic light emitting diode and method of preparation thereof), Patent, PI
2013700871, 2013, (National)
2. ENHANCED ELECTRON INJECTION ORGANIC LIGHT EMITTING DIODE, Patent, PI
2013003279, 2014, (National)
3. A Method of tuning an indium tin oxide (ITO) work function, Patent, PI 2014700191,
2014, (National)
4. Organic LED has non-cross linked emissive layer consisting of electron and hole
transporting hosts doped with electron blue phosphorescent emitters where non-
emissive hole transporting layer is cross-lined materials, Patent, WO2014193215-A1,
2014, (International)
5. PHOLED AND METHOD OF FABRICATING THEREOF, Patent, PI 2015704576 , 2016,
(National)
6. PHOSPHORESCENT ORGANIC LIGHT EMITTING DIODE (PHOLED) MATERIAL, Patent, PI
2015703855, 2015, (National)
29. People who are involved in this Project
University Malaya, Physics Department
1. Woon Kai Lin
2. Yeo Keat Hoe
3. Thomas J Whitcher
4. Noor Azrina Talik
5. Calvin Ng
6. Wang Seng Wong
University Malaya, Chemistry
Department
1. Azhar Arrifin
2. Zainal A. Hassan
3. Nurul Nadia
4. Bee Kian Ong
National Tsing Hua University, Chemical
Engineering Department
1. Show-An Chen
Thailand Synchrotron Light Source,
Thailand
1. Narong Chanlek
2. Hideki Nakajima
3. Thainit Saisopa
4. Prayoon Songsiriritthigul
Department of Polymer Chemistry and
Technology, Kaunas University of
Technology, Lithuania
1. Raimonda Griniene
2. Saulius Grigalevicius
University Tenaga Nasional, College of
Engineering
1. Dr Yap Boon Kar
University of Hull
1. Mary O’ Neill
30. 32
ACKNOWLEDGEMENT
Funders
1. UM Postgraduate Research Grant (PPP) PG071-2013A, PG112-2012B
2. MOHE Fundamental Research Grant (FRGS) FP005-2013A
3. MOSTI E-science (16-02-03-6030)
4 University Malaya Chancellery Research Grant (C-HIR)
(UM.C/625/1/HIR/195) and (UM.C/625/1/HIR/208)
5 UK Royal Society Travel Grant
6 Itramas Technology Sdn Bhd
~ RM 1.5 million is spent on this project over 5 years
(equipment, consumables, human capital)