Download or read book Charge Carrier Balance in Lead Halide Perovskite Light Emitting Diodes written by Matthew R. Chua and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Charge balance in light emitting diodes (LEDs) is a critical determinant of their performance. Charge balance is directly related to the External Quantum Efficiency (EQE), and is thought to have additional effects on device endurance and stability. In this thesis I present a series of experiments and simulations to study the charge balance in Lead Halide Perovskite (LHP) emitter LEDs. These LHP LEDs, particularly Near-Infrared Emitters have demonstrated high EQE, and promising lifetime.However for many other emission wavelengths their performance and endurance is lacking. I first present a modified simultaneous Photoluminescence-Electroluminesence (PLEL) measurement, along with two methods of calibrating the absolute photon flux absorbed, namely Short-circuit current, and Absorption from reflection. This allows the determination of absolute PL efficiency in the device relative to EL efficiency, to obtain an absolute measure of charge balance. Our measurements suggest that in the prototypical high efficiency NIR ITO/ZnO/LHP/TFB/MoO3/Al planar structure, the charge efficiency or [eta]CB is 0.83-0.91 , consistent with the high observed EQE of 16-17%. Next a different hole transport layer poly-TPD is introduced and the device studied relative to the original TFB case. We find that although poly-TPD devices have charge balance approximately 1.3x worse relative to TFB devices, this is insufficient to account for the 3x difference in device EQE when considering the relative PL quantum yields (PLQY) of the emitter under partially-complete stack measurements. By performing PL quantum yield measurements in-situ on a device under hybrid electrical-optical excitation, it is found that the LHP in-device PLQY is increased significantly and transiently by electrical excitation, which allows us to resolve the contradictory charge balance and EQE results. These experiments are supported by transfer matrix based optical simulations that allow us to account for the possible optical effects encountered in the different PLQY measurement conditions. Optical simulations are also used to convert the observed external PLQY to Internal Quantum Efficiency, [eta]QY , for a standard comparison across all measurements. This thesis demonstrates the effectiveness of the quasi-DC PLEL measurement in determining absolute charge balance in a LHP device. This method can be further applied to a broader range of LHP devices to gain greater understanding of the effect charge transport layers and LHP emitters have on each other when used to create electrically pumped light emitting systems.

Download or read book Multifunctional Organic Inorganic Halide Perovskite written by Nam-Gyu Park and published by CRC Press. This book was released on 2022-03-10 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt: Perovskite is a well-known structure with the chemical formula ABX3, where A and B are cations coordinated with 12 and 6 anions, respectively, and X is an anion. When a halogen anion is used, the monovalent A and divalent B cations can be stabilized with respect to a tolerance factor ranging from ~0.8 to 1. Since the first report on ~10% efficiency and long-term stability of solid-state perovskite solar cells (PSCs) in 2012 and two subsequent seed reports on perovskite-sensitized solar cells in 2009 and 2011, PSCs have received increasing attention. The power conversion efficiency of PSCs was certified to be more than 25% in 2020, surpassing thin-film solar cell technologies. Methylammonium or formamidinium organic ion–based lead iodide perovskite has been used for high-efficiency PSCs. The first report on solid-state PSCs triggered perovskite photovoltaics, leading to more than 23,000 publications as of October 2021. In addition, halide perovskite has shown excellent performance when applied to light-emitting diodes (LEDs), photodetectors, and resistive memory, indicating that halide perovskite is multifunctional. This book explains the electro-optical and ferroelectric properties of perovskite and details the recent progress in scalable and tandem PSCs as well as perovskite LEDs and resistive memory. It is a useful textbook and self-help study guide for advanced undergraduate- and graduate-level students of materials science and engineering, chemistry, chemical engineering, and nanotechnology; for researchers in photovoltaics, LEDs, resistive memory, and perovskite-related opto-electronics; and for general readers who wish to gain knowledge about halide perovskite.

Download or read book Quantum dot Based Light emitting Diodes written by Morteza Sasani Ghamsari and published by BoD – Books on Demand. This book was released on 2017-10-25 with total page 171 pages. Available in PDF, EPUB and Kindle. Book excerpt: Quantum dot-based light emitting diodes were assigned to bringing together the latest and most important progresses in light emitting diode (LED) technologies. In addition, they were dedicated to gain the perspective of LED technology for all of its advancements and innovations due to the employment of semiconductor nanocrystals. Highly selective, the primary aim was to provide a visual source for high-urgency work that will define the future directions relating to the organic light emitting diode (OLED), with the expectation for lasting scientific and technological impact. The editor hopes that the chapters verify the realization of the mentioned aims that have been considered for editing of this book. Due to the rapidly growing OLED technology, we wish this book to be useful for any progress that can be achieved in future.

Download or read book Perovskite Light Emitting Diodes written by Hong Meng and published by John Wiley & Sons. This book was released on 2024-01-03 with total page 373 pages. Available in PDF, EPUB and Kindle. Book excerpt: Perovskite Light Emitting Diodes An introduction to revolutionary display technology Perovskite Light Emitting Diodes, commonly referred to as Pe-LEDs, leverage a perovskite nanocrystal core to engender a luminous and efficient diode, holding the potential to bring about a paradigm shift in the realm of display technology. In recent times, Pe-LEDs have garnered substantial industrial interest due to their intrinsic capability to exhibit a diverse array of colors with exceptional fidelity, their operation at low voltage thresholds, and their straightforward structural composition. The prospective implications for enabling cost-effective, heightened-performance flat-panel displays as well as flexible display solutions remain notably profound. Perovskite Light Emitting Diodes: Materials and Devices presents a comprehensive and insightful overview of these diodes and their multifaceted applications. Commencing with an incisive exploration of the historical trajectory of this technology, alongside a delineation of its foundational materials and intricate device architectures, this compendium provides a gateway into both contemporaneous state-of-the-art deployments and the vanguard of ongoing research endeavors directed towards charting future advancements. Perovskite Light Emitting Diodes readers will also find: Stability analysis for different Pe-LED devices, a key aspect of creating physical displays Authorship by an established expert in organic electronics Detailed discussion of perovskite preparation methods including ultrasonic, solvent heat, thermal injection, and many more Perovskite Light Emitting Diodes is ideal for materials scientists, electrical engineers, solid state chemists, solid state physicists, inorganic chemists, and any researchers or engineers working with display technology.

Download or read book Halide Perovskites written by Tze-Chien Sum and published by John Wiley & Sons. This book was released on 2019-03-25 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt: Real insight from leading experts in the field into the causes of the unique photovoltaic performance of perovskite solar cells, describing the fundamentals of perovskite materials and device architectures. The authors cover materials research and development, device fabrication and engineering methodologies, as well as current knowledge extending beyond perovskite photovoltaics, such as the novel spin physics and multiferroic properties of this family of materials. Aimed at a better and clearer understanding of the latest developments in the hybrid perovskite field, this is a must-have for material scientists, chemists, physicists and engineers entering or already working in this booming field.

Download or read book Multifunctional Organic Inorganic Halide Perovskite written by Nam-Gyu Park and published by Jenny Stanford Publishing. This book was released on 2022-02-28 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book details the recent progress in halide perovskite photovoltaics, LEDs, and resistive memory, as well as the fundamentals of organic-inorganic halide perovskite.

Download or read book Lead Halide Perovskite Solar Cells written by David J. Fisher and published by Materials Research Forum LLC. This book was released on 2020-06-05 with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lead halide perovskite materials have a huge potential in solar cell technology. They offer the combined advantages of low-cost preparation and high power-conversion efficiency. The present review focusses on the following topics: Power Conversion Efficiency; Electron Transport, Hole Transport and Interface Layers; Material Preparation; Cesium-Doped Lead-Halide Perovskites; Formamidinium-Doped Lead-Halide Perovskites; Methylammonium Lead-Halide Perovskites; Hysteresis, Stability and Toxicity Problems. The book references 334 original resources and includes their direct web link for in-depth reading. Keywords: Solar Cells, Lead Halide Perovskite Materials, Cesium-Doped Lead-Halide Perovskites, Formamidinium-Doped Lead-Halide Perovskites, Methylammonium Lead-Halide Perovskites, Electron-Transport Layer, Hole-Transport Layer, Interface Layers, Hysteresis Problem, Stability Problem, Toxicity Problem.

Download or read book Metal Halide Perovskites and Perovskite Related Hybrids for Blue and White Light Emitting Diodes written by Michael Debebe Worku and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Metal halide perovskites have received significant attention in the past decade as a promising class of material for energy harvesting, light emission and detection as well as various other solid-state devices. The easy solution processability, high defect tolerance, abundance of raw materials and exceptional optoelectronic properties have warranted intense investigation into their fundamental material physics and their device integration. Particularly, metal halide perovskite light-emitting diodes (LEDs) are thought to hold promise for next generation displays due to their narrow and tunable emission, high radiative efficiency and easy processability. For instance, red and green perovskite LEDs have now achieved the high external quantum efficiency required for commercial applications, on par with more mature lighting technologies such as organic LEDs and quantum dot LEDs. However, there are still several roadblocks that need to be overcome before perovskite LEDs can be considered a commercially viable technology. These challenges include, device stability, material toxicity, mass-production and development of efficient blue LEDs. The development of efficient blue LEDs is a major milestone in any display technology as it allows the production of multi-color images by combining the three primary colors red, green and blue (RGB). Similarly, the development of efficient white LEDs with excellent white light quality displaying high color rendering indices is also as important for solid-state lighting applications. In this dissertation, we explore two major themes related to the use of perovskites and perovskite related metal halide hybrids in light-emitting applications. The first and the broader work involves the study of various strategies to enable the realization of efficient blue perovskite LEDs. Three of the main challenges in obtaining efficient blue perovskite LEDs have been identified as band gap and emission tuning, poor radiative efficiency of perovskite blue emitters and charge carrier imbalance that results in suboptimal device performance. These issues are addressed in the first theme of this dissertation by introducing effective band gap and emission tuning strategies, improving radiative efficiency of blue perovskite emitters through trap passivation and engineering the energy band edges of perovskite thin films to obtain favorable band alignment and enhanced charge balance. In this theme, two methods are presented in chapter 2 and 3 to achieve band gap and emission control while ensuring spectral stability. These include the synthesis of perovskite hollow nanocrystals and phase control of perovskite multiple quantum well thin films. Perovskite hollow nanocrystals are shown to enable band gap and emission tuning through the formation of a hollow 3D crystal structure and quantum confinement. Reduced grain boundaries and passivation of surface trap sites in these nanocrystalline thin films are also shown to result in high radiative efficiencies. Although the formation of perovskite quantum wells has been shown to be an effective strategy to control the band gap and emission, the crystallization of multiple quantum well phases during thin film formation and fast energy funneling across phases has limited the application of perovskite quantum wells in color tunable and blue LEDs. In chapter 3, we show the addition of diammonium salts enables phase control in perovskite multiple quantum well thin films, resulting in color tunable emission. The presence of diammonium salts was also found to increase radiative efficiency enabling the fabrication of pure blue perovskite LEDs with good efficiency. Finally, energy band edge control of quasi-2D perovskites is also presented as a viable solution to charge injection barriers that appear due to unfavorable band alignment in blue perovskite LEDs. By modifying the dipole moment of organic spacer cations in quasi-2D perovskites through the addition of electron donating or withdrawing substituent groups, rational band edge control is achieved which enables improved blue LED performance due to enhanced charge balance. In the second theme of this dissertation, the use of low-dimensional metal halide hybrids in broadband white LEDs for high color quality applications is shown. The broadband emission spectra of low-dimensional metal halide hybrids are shown to be ideal for white light applications that require full spectrum coverage and high color rendering. The dissertation concludes by presenting a few exciting routes that could be explored to further improve the performance of blue and white LEDs based on perovskites and perovskite related materials. The work presented in this dissertation contributes to the field of perovskite LEDs by exploring the structure-processing-property-performance phase space and providing alternative routes to obtain spectrally stable and efficient blue perovskite LEDs as well as excellent light quality white LEDs, which could help transition perovskite LEDs to commercial viability.

Download or read book Halide Perovskite Semiconductors written by Yuanyuan Zhou and published by John Wiley & Sons. This book was released on 2023-12-22 with total page 517 pages. Available in PDF, EPUB and Kindle. Book excerpt: Halide Perovskite Semiconductors Enables readers to acquire a systematic and in-depth understanding of various fundamental aspects of halide perovskite semiconductors Halide Perovskite Semiconductors: Structures, Characterization, Properties, and Phenomena covers the most fundamental topics with regards to halide perovskites, including but not limited to crystal/defect theory, crystal chemistry, heterogeneity, grain boundaries, single-crystals/thin-films/nanocrystals synthesis, photophysics, solid-state ionics, spin physics, chemical (in)stability, carrier dynamics, hot carriers, surface and interfaces, lower-dimensional structures, and structural/functional characterizations. Included discussions on the fundamentals of halide perovskites aim to expand the basic science fields of physics, chemistry, and materials science. Edited by two highly qualified researchers, Halide Perovskite Semiconductors includes specific information on: Crystal/defect theory of halide perovskites, crystal chemistry of halide perovskites, and processing and microstructures of halide perovskites Single-crystals of halide perovskites, nanocrystals of halide perovskites, low-dimensional perovskite crystals, and nanoscale heterogeneity of halide perovskites Carrier mobilities and dynamics in halide perovskites, light emission of halide perovskites, photophysics and ultrafast spectroscopy of halide perovskites Hot carriers in halide perovskites, correlating photophysics with microstructures in halide perovskites, chemical stability of halide perovskites, and solid-state ionics of halide perovskites Readers can find solutions to technological issues and challenges based on the fundamental knowledge gained from this book. As such, Halide Perovskite Semiconductors is an essential in-depth treatment of the subject, ideal for solid-state chemists, materials scientists, physical chemists, inorganic chemists, physicists, and semiconductor physicists.

Download or read book Lead Halide Perovskite Solar Cells written by Fisher, D.J. and published by Materials Research Forum LLC. This book was released on 2020-06-06 with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lead halide perovskite materials have a huge potential in solar cell technology. They offer the combined advantages of low-cost preparation and high power-conversion efficiency. The present review focusses on the following topics: Power Conversion Efficiency; Electron Transport, Hole Transport and Interface Layers; Material Preparation; Cesium-Doped Lead-Halide Perovskites; Formamidinium-Doped Lead-Halide Perovskites; Methylammonium Lead-Halide Perovskites; Hysteresis, Stability and Toxicity Problems. The book references 334 original resources and includes their direct web link for in-depth reading. Keywords: Solar Cells, Lead Halide Perovskite Materials, Cesium-Doped Lead-Halide Perovskites, Formamidinium-Doped Lead-Halide Perovskites, Methylammonium Lead-Halide Perovskites, Electron-Transport Layer, Hole-Transport Layer, Interface Layers, Hysteresis Problem, Stability Problem, Toxicity Problem.

Download or read book Perovskite Quantum Dots written by Ye Zhou and published by Springer Nature. This book was released on 2020-08-27 with total page 374 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book addresses perovskite quantum dots, discussing their unique properties, synthesis, and applications in nanoscale optoelectronic and photonic devices, as well as the challenges and possible solutions in the context of device design and the prospects for commercial applications. It particularly focuses on the luminescent properties, which differ from those of the corresponding quantum dots materials, such as multicolor emission, fluorescence narrowing, and tunable and switchable emissions from doped nanostructures. The book first describes the characterization and fabrication of perovskite quantum dots. It also provides detailed methods for analyzing the electrical and optical properties, and demonstrates promising applications of perovskite quantum dots. Furthermore, it presents a series of optoelectronic and photonic devices based on functional perovskite quantum dots, and explains the incorporation of perovskite quantum dots in semiconductor devices and their effect of the performance. It also explores the challenges related to optoelectronic devices, as well as possible strategies to promote their commercialization. As such, this book is a valuable resource for graduate students and researchers in the field of solid-state materials and electronics wanting to gain a better understanding of the characteristics of quantum dots, and the fundamental optoelectronic properties and operation mechanisms of the latest perovskite quantum dot-based devices.

Download or read book Advanced Nanomaterials for Solar Cells and Light Emitting Diodes written by Feng Gao and published by Elsevier. This book was released on 2019-04-10 with total page 552 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advanced Nanomaterials for Solar Cells and Light Emitting Diodes discusses the importance of nanomaterials as the active layers in solar cells and light emitting diodes (LEDs), along with the progress of nanomaterials as the electron and hole transporting layers. Specifically, the book reviews the use of nano-morphology of polymers, small molecules, and the organic-inorganic perovskites as the active layers in solar cells and LEDs. The design, fabrication and properties of metal-oxide-based nano-structures as electron and hole transporting layers are also reviewed. In addition, the development of plasmonic nanomaterials for solar cells and LEDs is discussed. Each topic in this book includes an overview of the materials system from principles to process. The advantages, disadvantages and related methodologies are highlighted. The book includes applications based on materials and emphasize how to improve the performance of solar cells and LEDs by the materials design, with a focus on nanomaterials. - Provides latest research on nanostructured materials including small molecules, polymers, organic-inorganic perovskites, and many other relevant materials systems for solar cells and LEDs - Addresses each promising materials system from principles to process, detailing the advantages and disadvantages of the most relevant methods of processing and fabrication - Looks ahead to most likely techniques to improve performance of solar cells and light emitting diodes

Download or read book Stability Study in Lead halide Perovskite Light emitting Diodes written by Ziyue Yi and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Diode Lasers and Photonic Integrated Circuits written by Larry A. Coldren and published by John Wiley & Sons. This book was released on 2012-03-02 with total page 752 pages. Available in PDF, EPUB and Kindle. Book excerpt: Diode Lasers and Photonic Integrated Circuits, Second Edition provides a comprehensive treatment of optical communication technology, its principles and theory, treating students as well as experienced engineers to an in-depth exploration of this field. Diode lasers are still of significant importance in the areas of optical communication, storage, and sensing. Using the the same well received theoretical foundations of the first edition, the Second Edition now introduces timely updates in the technology and in focus of the book. After 15 years of development in the field, this book will offer brand new and updated material on GaN-based and quantum-dot lasers, photonic IC technology, detectors, modulators and SOAs, DVDs and storage, eye diagrams and BER concepts, and DFB lasers. Appendices will also be expanded to include quantum-dot issues and more on the relation between spontaneous emission and gain.

Download or read book Charge Carrier Dynamics in Organo Lead Halide Perovskites written by Mahmoud Saeed Qaid Mohammad Hezam and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Mots-clés de l'auteur: organo lead halide perovskite ; perovskite solar cells ; photoluminescence ; time-resolved photoluminescence ; cathodoluminescence ; UV-induced damage ; amplified spontaneous emission.

Download or read book Metal Halide Perovskites for Generation Manipulation and Detection of Light written by Juan P. Martínez-Pastor and published by Elsevier. This book was released on 2023-07-20 with total page 574 pages. Available in PDF, EPUB and Kindle. Book excerpt: Metal Halide Perovskites for Generation, Manipulation and Detection of Light covers the current state and future prospects of lead halide perovskite photonics and photon sources, both from an academic and industrial point-of-view. Advances in metal halide perovskite photon sources (lasers) based on thin films, microcrystals and nanocrystals are comprehensively reviewed, with leading experts contributing current advances in theory, fundamental concepts, fabrication techniques, experiments and other important research innovations. This book is suitable for graduate students, researchers, scientists and engineers in academia and R&D in industry working in the disciplines of materials science and engineering. - Includes comprehensive reviews from academic and industrial perspectives of current trends in the field of metal halide perovskite for photonics - Provides an up-to-date look at the most recent and upcoming applications in metal halide perovskite photonics, such as; photodetectors, lighting, lasing, nonlinear photonics and quantum technologies - Discusses future prospective trends and envisioned applications of metal halide perovskites, from near-UV to near-IR photonics

Download or read book Application of Lead halide Perovskite Nanocrystals in Light emitting Diodes written by Tassilo Naujoks and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: