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Investigation And Fabrication Of Gan Based Blue Light Emitting Diode With High Light Extraction And Quantum Efficiency
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Book Synopsis Investigation and Fabrication of GaN-based Blue Light Emitting Diode with High Light Extraction and Quantum Efficiency by :
Download or read book Investigation and Fabrication of GaN-based Blue Light Emitting Diode with High Light Extraction and Quantum Efficiency written by and published by . This book was released on 2015 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis High Brightness Light Emitting Diodes by :
Download or read book High Brightness Light Emitting Diodes written by and published by Academic Press. This book was released on 1998-02-09 with total page 489 pages. Available in PDF, EPUB and Kindle. Book excerpt: Volume 48in the Semiconductors and Semimetals series discusses the physics and chemistry of electronic materials, a subject of growing practical importance in the semiconductor devices industry. The contributors discuss the current state of knowledge and provide insight into future developments of this important field.
Book Synopsis Light Extraction from GaN-based Light Emitting Diodes with a Noninvasive Two-dimensional Photonic Crystal by : Tuan Anh Truong
Download or read book Light Extraction from GaN-based Light Emitting Diodes with a Noninvasive Two-dimensional Photonic Crystal written by Tuan Anh Truong and published by . This book was released on 2012 with total page 54 pages. Available in PDF, EPUB and Kindle. Book excerpt: A noninvasive fabrication process involving soft nanoimprint lithography is used to pattern a photonic crystal (PhC) in titania film for enhanced light extraction from a GaN light emitting diode (LED). This technique avoids damaging the LED structure by the etching process, while photoluminescence measurements show extracted modes emitted from the quantum wells which agree well with modeling. A light extraction improvement of 1.8 times is measured using this noninvasive PhC. Contacts are made on the LED structure without PhC. The device works properly and shows good electrical properties. A drop in the external quantum efficiency is observed under high forward bias and is attributed to Auger recombination processes.
Book Synopsis Nitride Semiconductor Light-Emitting Diodes (LEDs) by : Jian-Jang Huang
Download or read book Nitride Semiconductor Light-Emitting Diodes (LEDs) written by Jian-Jang Huang and published by Woodhead Publishing. This book was released on 2014-02-14 with total page 673 pages. Available in PDF, EPUB and Kindle. Book excerpt: The development of nitride-based light-emitting diodes (LEDs) has led to advancements in high-brightness LED technology for solid-state lighting, handheld electronics, and advanced bioengineering applications. Nitride Semiconductor Light-Emitting Diodes (LEDs) reviews the fabrication, performance, and applications of this technology that encompass the state-of-the-art material and device development, and practical nitride-based LED design considerations. Part one reviews the fabrication of nitride semiconductor LEDs. Chapters cover molecular beam epitaxy (MBE) growth of nitride semiconductors, modern metalorganic chemical vapor deposition (MOCVD) techniques and the growth of nitride-based materials, and gallium nitride (GaN)-on-sapphire and GaN-on-silicon technologies for LEDs. Nanostructured, non-polar and semi-polar nitride-based LEDs, as well as phosphor-coated nitride LEDs, are also discussed. Part two covers the performance of nitride LEDs, including photonic crystal LEDs, surface plasmon enhanced LEDs, color tuneable LEDs, and LEDs based on quantum wells and quantum dots. Further chapters discuss the development of LED encapsulation technology and the fundamental efficiency droop issues in gallium indium nitride (GaInN) LEDs. Finally, part three highlights applications of nitride LEDs, including liquid crystal display (LCD) backlighting, infrared emitters, and automotive lighting. Nitride Semiconductor Light-Emitting Diodes (LEDs) is a technical resource for academics, physicists, materials scientists, electrical engineers, and those working in the lighting, consumer electronics, automotive, aviation, and communications sectors. Reviews fabrication, performance, and applications of this technology that encompass the state-of-the-art material and device development, and practical nitride-based LED design considerations Covers the performance of nitride LEDs, including photonic crystal LEDs, surface plasmon enhanced LEDs, color tuneable LEDs, and LEDs based on quantum wells and quantum dots Highlights applications of nitride LEDs, including liquid crystal display (LCD) backlighting, infra-red emitters, and automotive lighting
Book Synopsis The Novel Investigation and Fabrication of High Brightness GaN-based Light Emitting Diodes by : 郭得山
Download or read book The Novel Investigation and Fabrication of High Brightness GaN-based Light Emitting Diodes written by 郭得山 and published by . This book was released on 2012 with total page 117 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Optoelectronic Nanodevices by : Minas M. Stylianakis
Download or read book Optoelectronic Nanodevices written by Minas M. Stylianakis and published by MDPI. This book was released on 2020-04-15 with total page 338 pages. Available in PDF, EPUB and Kindle. Book excerpt: During the last decade, novel graphene related materials (GRMs), perovskites, as well as metal oxides and other metal nanostructures have received the interest of the scientific community. Due to their extraordinary physical, optical, thermal, and electrical properties, which are correlated with their 2D ultrathin atomic layer structure, large interlayer distance, ease of functionalization, and bandgap tunability, these nanomaterials have been applied in the development or the improvement of innovative optoelectronic applications, as well as the expansion of theoretical studies and simulations in the fast-growing fields of energy (photovoltaics, energy storage, fuel cells, hydrogen storage, catalysis, etc.), electronics, photonics, spintronics, and sensing devices. The continuous nanostructure-based applications development has provided the ability to significantly improve existing products and to explore the design of materials and devices with novel functionalities. This book demonstrates some of the most recent trends and advances in the interdisciplinary field of optoelectronics. Most articles focus on light emitting diodes (LEDs) and solar cells (SCs), including organic, inorganic, and hybrid configurations, whereas the rest address photodetectors, transistors, and other well-known dynamic optoelectronic devices. In this context, this exceptional collection of articles is directed at a broad scientific audience of chemists, materials scientists, physicists, and engineers, with the goals of highlighting the potential of innovative optoelectronic applications incorporating nanostructures and inspiring their realization.
Book Synopsis Investigation and Fabrication of GaN-based Light-Emitting Diodes by Nanostructures and Patterned Sapphire Substrates by : 高健智
Download or read book Investigation and Fabrication of GaN-based Light-Emitting Diodes by Nanostructures and Patterned Sapphire Substrates written by 高健智 and published by . This book was released on 2011 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Fabrication and Analysis of GaN-Based High-Speed Blue Light-Emitting Diodes by : 蕭佳晏
Download or read book Fabrication and Analysis of GaN-Based High-Speed Blue Light-Emitting Diodes written by 蕭佳晏 and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Development of Gallium Nitride-based Ultraviolet and Visible Light-emitting Diodes Using Hydride Vapor-phase Epitaxy and Molecular Epitaxy by : Jasper Sicat Cabalu
Download or read book Development of Gallium Nitride-based Ultraviolet and Visible Light-emitting Diodes Using Hydride Vapor-phase Epitaxy and Molecular Epitaxy written by Jasper Sicat Cabalu and published by . This book was released on 2006 with total page 630 pages. Available in PDF, EPUB and Kindle. Book excerpt: ABSTRACT: Much of the work done on ultraviolet (UV) and visible III-Nitrides-based light emitting diodes (LEDs) involves growth by metal-organic chemical vapor deposition (MOCVD). In this dissertation, the growth, development, and fabrication of III-Nitrides-based UV and visible LEDs with very high photon conversion and extraction efficiencies using hydride vapor-phase epitaxy (HVPE) and radio frequency (rf) plasma-assisted molecular beam epitaxy (PAMBE) is presented. High-power electrically-pumped UV-LEDs based on GaN/AlGaN multiple quantum wells (MQWs) emitting at 340 nm and 350 nm have been fabricated in a flip-chip configuration and evaluated. Under pulsed operation, UV-LEDs emitting at 340 nm have output powers that saturate, due to device heating, at approximately 3 mW. Devices emitting at 350 nm show DC operation output powers as high as 4.5 mW under 200 mA drive current. These results were found to be equivalent with those of UV-LEDs produced by the MOCVD and HVPE methods. The concept of using textured MQWs on UV-LED structures was tested by optical pumping of GaN/AlGaN MQWs grown on textured GaN templates. Results show highly enhanced (>700 times) blue-shifted photoluminescence (PL) at 360 nm compared to similarly produced MQWs on smooth GaN templates whose PL emission is red-shifted. These results are attributed partly to enhancement in light extraction efficiency (LEE) and partly to enhancement in internal quantum efficiency (IQE). The origin of the increase in IQE is partly due to reduction of the quantum-confined Stark effect (QCSE) on QW-planes not perpendicular to the polarization direction and partly due to charge redistribution in the QWs caused by the polarization component parallel to the planes of the QWs. Similar studies have been done for visible LEDs using InGaN/GaN MQWs. Growth of LED structures on textured GaN templates employing textured MQW-active regions resulted in the production of dichromatic (430 nm and 530 nm) phosphorless white LEDs with good electrical characteristics. We attribute this behavior to different incorporation of In in different QW-planes. These studies show that textured MQW-based LEDs not only offers the benefit of enhanced IQE and LEE, but also the benefit of producing efficient white LEDs without the use of phosphor.
Book Synopsis III-Nitride Based Light Emitting Diodes and Applications by : Tae-Yeon Seong
Download or read book III-Nitride Based Light Emitting Diodes and Applications written by Tae-Yeon Seong and published by Springer Science & Business Media. This book was released on 2014-07-08 with total page 434 pages. Available in PDF, EPUB and Kindle. Book excerpt: Light emitting diodes (LEDs) are already used in traffic signals, signage lighting, and automotive applications. However, its ultimate goal is to replace traditional illumination through LED lamps since LED lighting significantly reduces energy consumption and cuts down on carbon-dioxide emission. Despite dramatic advances in LED technologies (e.g., growth, doping and processing technologies), however, there remain critical issues for further improvements yet to be achieved for the realization of solid-state lighting. This book aims to provide the readers with some contemporary LED issues, which have not been comprehensively discussed in the published books and, on which the performance of LEDs is seriously dependent. For example, most importantly, there must be a breakthrough in the growth of high-quality nitride semiconductor epitaxial layers with a low density of dislocations, in particular, in the growth of Al-rich and and In-rich GaN-based semiconductors. The materials quality is directly dependent on the substrates used, such as sapphire, Si, etc. In addition, efficiency droop, growth on different orientations and polarization are also important. Chip processing and packaging technologies are key issues. This book presents a comprehensive review of contemporary LED issues. Given the interest and importance of future research in nitride semiconducting materials and solid state lighting applications, the contents are very timely. The book is composed of chapters written by leading researchers in III-nitride semiconducting materials and device technology. This book will be of interest to scientists and engineers working on LEDs for lighting applications. Postgraduate researchers working on LEDs will also benefit from the issues this book provides.
Book Synopsis Quantum Efficiency Enhancement for Gan Based Light-emitting Diodes and Vertical Cavity Surface-emitting Lasers by : Fan Zhang
Download or read book Quantum Efficiency Enhancement for Gan Based Light-emitting Diodes and Vertical Cavity Surface-emitting Lasers written by Fan Zhang and published by . This book was released on 2014 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis explores the improvement of quantum efficiencies for InGaN/GaN heterostructures and their applications in light-emitting diodes (LEDs) and vertical cavity surface-emitting lasers (VCSELs). Different growth approaches and structural designs were investigated to identify and address the major factors limiting the efficiency. (1) Hot electron overflow and asymmetrical electron/hole injection were found to be the dominant reasons for efficiency degradation in nitride LEDs at high injection; (2) delta p-doped InGaN quantum barriers were employed to improve hole concentration inside the active region and therefore improve hole injection without sacrificing the layer quality; (3) InGaN active regions based on InGaN multiple double-heterostructures (DHs) were developed to understand the electron and hole recombination mechanisms and achieve high quantum efficiency and minimal efficiency droop at high injection; (4) the effect of stair-case electron injectors (SEIs) has been investigated with different active region designs and SEIs with optimized thickness greatly mitigated electron overflow without sacrificing material quality of the active regions. The active regions showing promising performance in LEDs were incorporated into VCSEL designs. Hybrid VCSEL structures with bottom semiconductor AlN/GaN and a top dielectric SiO2/SiNx DBRs have been investigated, and quality factors as high as 1300 have been demonstrated. Finally, VCSEL structures with all dielectric DBRs have been realized by employing a novel ELO-GaN growth method that allowed integration of a high quality InGaN cavity active region with a dielectric bottom DBR without removal of the substrate while forming a current aperture through the ideally dislocation-free region. The full-cavity structures formed as such exhibited quality factors 500 across the wafer.
Book Synopsis Progress and Prospects of GaN-based LEDs Using Nanostructures*Project Supported by the National Natural Science Foundation of China (Grant No. 61334009), the National High Technology Research and Development Program of China (Grant Nos. 2015AA03A101 and 2014BAK02B08), China International Science and Technology Cooperation Program (Grant No. 2014DFG62280), the "Import Outstanding Technical Talent Plan" and "Youth Innovation Promotion Association Program" of the Chinese Academy of Sciences by :
Download or read book Progress and Prospects of GaN-based LEDs Using Nanostructures*Project Supported by the National Natural Science Foundation of China (Grant No. 61334009), the National High Technology Research and Development Program of China (Grant Nos. 2015AA03A101 and 2014BAK02B08), China International Science and Technology Cooperation Program (Grant No. 2014DFG62280), the "Import Outstanding Technical Talent Plan" and "Youth Innovation Promotion Association Program" of the Chinese Academy of Sciences written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Progress with GaN-based light emitting diodes (LEDs) that incorporate nanostructures is reviewed, especially the recent achievements in our research group. Nano-patterned sapphire substrates have been used to grow an AlN template layer for deep-ultraviolet (DUV) LEDs. One efficient surface nano-texturing technology, hemisphere-cones-hybrid nanostructures, was employed to enhance the extraction efficiency of InGaN flip-chip LEDs. Hexagonal nanopyramid GaN-based LEDs have been fabricated and show electrically driven color modification and phosphor-free white light emission because of the linearly increased quantum well width and indium incorporation from the shell to the core. Based on the nanostructures, we have also fabricated surface plasmon-enhanced nanoporous GaN-based green LEDs using AAO membrane as a mask. Benefitting from the strong lateral SP coupling as well as good electrical protection by a passivation layer, the EL intensity of an SP-enhanced nanoporous LED was significantly enhanced by 380%. Furthermore, nanostructures have been used for the growth of GaN LEDs on amorphous substrates, the fabrication of stretchable LEDs, and for increasing the 3-dB modulation bandwidth for visible light communication.
Book Synopsis Optics in Our Time by : Mohammad D. Al-Amri
Download or read book Optics in Our Time written by Mohammad D. Al-Amri and published by Springer. This book was released on 2016-12-12 with total page 509 pages. Available in PDF, EPUB and Kindle. Book excerpt: Light and light based technologies have played an important role in transforming our lives via scientific contributions spanned over thousands of years. In this book we present a vast collection of articles on various aspects of light and its applications in the contemporary world at a popular or semi-popular level. These articles are written by the world authorities in their respective fields. This is therefore a rare volume where the world experts have come together to present the developments in this most important field of science in an almost pedagogical manner. This volume covers five aspects related to light. The first presents two articles, one on the history of the nature of light, and the other on the scientific achievements of Ibn-Haitham (Alhazen), who is broadly considered the father of modern optics. These are then followed by an article on ultrafast phenomena and the invisible world. The third part includes papers on specific sources of light, the discoveries of which have revolutionized optical technologies in our lifetime. They discuss the nature and the characteristics of lasers, Solid-state lighting based on the Light Emitting Diode (LED) technology, and finally modern electron optics and its relationship to the Muslim golden age in science. The book’s fourth part discusses various applications of optics and light in today's world, including biophotonics, art, optical communication, nanotechnology, the eye as an optical instrument, remote sensing, and optics in medicine. In turn, the last part focuses on quantum optics, a modern field that grew out of the interaction of light and matter. Topics addressed include atom optics, slow, stored and stationary light, optical tests of the foundation of physics, quantum mechanical properties of light fields carrying orbital angular momentum, quantum communication, and Wave-Particle dualism in action.
Book Synopsis Status of GaN-based Green Light-emitting Diodes *Project Supported by the Key Program of the National Natural Science Foundation of China (Grant No. 61334001), the National Natural Science Foundation of China (Grant Nos. 11364034 and 21405076), the National Key Technology Research and Development Program of the Ministry of Science and Technology of China (Grant No. 2011BAE32B01), and the National High Technology Research and Development Program of China (Grant No. 2011AA03A101). by :
Download or read book Status of GaN-based Green Light-emitting Diodes *Project Supported by the Key Program of the National Natural Science Foundation of China (Grant No. 61334001), the National Natural Science Foundation of China (Grant Nos. 11364034 and 21405076), the National Key Technology Research and Development Program of the Ministry of Science and Technology of China (Grant No. 2011BAE32B01), and the National High Technology Research and Development Program of China (Grant No. 2011AA03A101). written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: GaN-based blue light emitting diodes (LEDs) have undergone great development in recent years, but the improvement of green LEDs is still in progress. Currently, the external quantum efficiency (EQE) of GaN-based green LEDs is typically 30%, which is much lower than that of top-level blue LEDs. The current challenge with regard to GaN-based green LEDs is to grow a high quality InGaN quantum well (QW) with low strain. Many techniques of improving efficiency are discussed, such as inserting AlGaN between the QW and the barrier, employing prestrained layers beneath the QW and growing semipolar QW. The recent progress of GaN-based green LEDs on Si substrate is also reported: high efficiency, high power green LEDs on Si substrate with 45.2% IQE at 35 A/cm 2, and the relevant techniques are detailed.
Book Synopsis Investigation of Light Output Extraction Enhancement in GaN-based Light Emitting Diodes by : 林志堅
Download or read book Investigation of Light Output Extraction Enhancement in GaN-based Light Emitting Diodes written by 林志堅 and published by . This book was released on 2011 with total page 109 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Investigation and Fabrication of High Performance GaN- and AlGaInP-based Light Emitting Diodes by : 王培任
Download or read book Investigation and Fabrication of High Performance GaN- and AlGaInP-based Light Emitting Diodes written by 王培任 and published by . This book was released on 2012 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Electrical and Optical Studies on Modeling and Fabrication of Gallium Nitride (GaN) Based Optoelectronic Devices by : Asim Mohammed A. Noor Elahi
Download or read book Electrical and Optical Studies on Modeling and Fabrication of Gallium Nitride (GaN) Based Optoelectronic Devices written by Asim Mohammed A. Noor Elahi and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The work in this dissertation is divided into two parts. The first part is related to the study of integration optoelectronic devices, such as Schottky Barrier Diodes (SBDs) and Metal Semiconductor Field Effect Transistors (MESFETs), along with Light Emitting Diodes (LEDs) on the same electronic chip. The second part of this dissertation is concerned with the electrical and optical modeling of gap-free microdisplay devices of based on gallium nitride, GaN, the optical modeling of nanophosphor-coupled porous layers for color conversion in III-Nitride microLED arrays, and also with some experimental studies on the photochemical and thermal stabilities of QDs materials that are integrated in the structure of GaN microLED devices. It is concluded from the first part of this work that the buffer layer located at the interface of unintentionally doped GaN layer and sapphire substrate has a strong effect on the forward current properties of lateral-type GaN Schottky diodes and plannar GaN metal-semiconductor-field-effect-transistors (MESFETs) grown on sapphire substrates (chapter 2). Experimental and simulation results have revealed that the interfacial region is acting as a channel in which the current passes in between the device metallic contacts because of the high conductivity that arises from a significant number of threading dislocations that are decorated by impurities due to the large lattice mismatches between GaN and sapphire. Owing to the presence of the interfacial regions, the lateral Schottky diodes exhibit high current densities but without change in their on-state-voltage, whereas the planar MESFETs could hardly reach cut-off or show saturation behavior. As a result, GaN-based vertical metal-semiconductor field-effect transistors(MESFETs) on commercial light-emitting-diode (LED) epi-wafers was fabricated and designed to overcome the latter problem (chapter 3). Also, the devices studied were simulated using charge transport model for better understanding of the current-voltage relationship. It was found that shrinking the size of the drain pillar helps reaching cut-off at much lower gate bias, even at high carrier concentration of unintentionally doped GaN and also with considerable leakage current caused by the Schottky barrier lowering. From the second part of the dissertation, it is disclosed that the isolation barrier region offers a better performance of a microLED microdisplay by minimizing the light cross-talk between the microLED pixels (chapter 4). It was found from the optical modeling results that the light cross-talk between the microLED pixels including the illuminating one in the isolation barrier planar structure is decreased significantly compared to the light cross-talk from all the pixels including the illuminating one in the non-planar air gap conventional structure of a microdisplay. The electrical simulation results reveal that the cross-talk current depends on the implanted ions energy, implanted ions dose and the width of the isolation barrier. The cross-talk current between the devices is decreased and the number of the affected pixels in the same row of a microdisplay is also reduced by the increase of the impurity concentration in the isolation barriers since the implanted ions are introducing deep level traps which results in current isolation between devices. Since the current microLED arrays are monochromatic emitting devices, nanophosphor-coupled nanoporous layers in III-nitride microLED arrays has been used to create colorful microLED arrays. The structure of those devices has been numerically analyzed along with its impacts on the application of microLED matrices in colorful display panels (chapter 5). It is concluded from the computational analysis carried out in this project that there remain some key challenges that need to be addressed in order to use such a structure in developing full-color miroLED display panels that simultaneously preserve the high-resolution and efficiency performances of microLED display devices. The extraction efficiency of both excitation (blue) and down-conversion (red) light from a nanophosphor-coupled LED devices have been demonstrated to drop drastically beyond specific thresholds when the porosity and thickness of the porous down-conversion layer increases. Additionally, it is found from the simulation that the cross-talk of down-converted light between adjacent micro-LED pixels is substantially higher compared to the excitation light cross-talk due to the location of the phosphors in the pore cavities and the resultant strong scattering by the surrounding nanopores. Furthermore, the instability of QDs is still a serious concern for the implementation of those emissive materials in the microLED display panels. Therefore, in Chapter 6, experimental studies on the thermal and photochemical stabilities of multicolored microLED display panels are presented. This chapter studied the thermal and photochemical stabilities of a 15 micrometer-thick layer of mixed red, green, and blue quantum dots produced via spin-cast deposition over a blue microLED matrix. This study also looked at the optical properties of QDs-based multicolored microLEDs. The results in this work provided us with a basic understanding of the ultimate limit of QD performance in microLED devices. The stability assessment results support and inspire the use of red, green, and blue QDs layers in blue microLED matrices to produce full-color microLED devices. Such research will aid in the design and production of high-efficiency, high-performance micro-LED display panels. Finally, Chapter 7 presents suggestions for the proposed future research in the field related to the scope of investigation reported in this thesis.
