Download or read book Solution processed High performance Photovoltaics by 3D Perovskites Incorporated with 2D Perovskites written by Haodong Wu and published by . This book was released on 2021 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt: In recent years, the world storage of coal, oil, natural gas, and other sources of nonrenewable energy is becoming less and less, meanwhile the problem of energy shortage is becoming more and more emergent which will restrict the development of the international economy. Under this background, most countries begin to develop solar energy, which promotes the development of solar cells. As we know, solar cells can straightforwardly transform light into electricity through the photovoltaic effect, and currently silicon solar cell is the most sophisticated technology in commercialization. Nevertheless, because of the complexity of the fabrication technique and the high cost of silicon materials, it is not easy to cut its price substantially. Therefore, finding new materials and new methods to fabricate economic solar cells is necessary. Right now, the hot research topic in this field is perovskite solar cells (PSCs). This kind of solar cell has a special light-absorbing active layer, which is called organic inorganic hybrid perovskite (OIHP), the most common is methylammonium lead iodide (CH3NH3PbI3 or MAPbI3). This kind of PSC can be easily solution-processed, and the raw materials are less expensive, both make it cheap to process and simple to fabricate. Previous studies have shown that perovskite like MAPbI3 with a three-dimensional (3D) structure are highly efficient. But the poor stability limits its application. Thus, it is urgent to develop a novel kind of PSCs with both high efficiency and good stability. Here, we present two feasible methods, compositional engineering and interfacial engineering, to fabricate 2D:3D mixed PSCs and 2D/3D bilayer PSCs for achieving the goal of high-performance photovoltaics. In the first method, with the help of 4-fluoro-phenethylammonium (4F-PEA) organic spacer, the corresponding champion PSC can obtain a better device performance with a power convention efficiency (PCE) over 20%, as well as a better stability for 3000 hours with less than 40% loss in PCE at a relative humidity of 10%-15%. This novel 2D:3D mixed [(4F-PEA)2MA[subscript n-1]Pb[subscript]I[subscript3n+1]][subscript x]:MAPbI3 perovskite will provide an innovative method to fabricate high-performance PSCs with good stability. In the second method, the surface defect passivation of MAPbI3 perovskite films with binary organic spacer 3-phenyl-2-propen-1-amine/4-fluoro-phenethylammonium (PPA/4F-PEA) is reported. We found that a 2D layer (PPA)(4F-PEA)MA[subscript n-1]Pb[subscript n]I[subscript 3n+1] can be formed on the surface of MAPbI3 perovskite and achieve more efficient PSCs by reducing defects and inhibiting non-radiative recombination. The results show that the PCE of this kind of PSCs can reach above 20%. In addition, a open-circuit voltage (V[subscript OC]) up to 1.16 V can be obtained with the presence of the top 2D layer, which is 93% of Shockley-Queisser limit V[subscript OC] (1.25 V). Because of the hydrophobic nature of the top 2D layer, the optimized PSCs can maintain 97% of the initial PCE after 500 hours at a relative humidity of 10%-15%. The unique idea of the 2D layer as a moisture-proof protection window, maintaining efficient 3D perovskite structure provides clues for the development of high-performance perovskites and paves the way for the wide application of efficient and stable PSCs shortly.

Download or read book High Performance Solution processed Perovskite Photovoltaics by Novel Materials written by Rui Chen (Polymer Engineer) and published by . This book was released on 2021 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt: Organic-inorganic halide perovskites have been the next generation photovoltaics as it excellent photoelectronic properties. This thesis mainly reported novel photoactive layer materials called low-dimension perovskite and their corresponding PVs, including solar cells and photodetectors. In CHAPTER I, the fundamental physic of perovskite materials and overviews of perovskite solar cells and photodetectors were reported. In CHAPTER II, enhanced device performance of perovskite photovoltaics by one-step self-assembled (PEA)2(MA)n-1PbnI3n+1/MAPbI3 2D/3D bilayer thin films post-treated by 1-butanol (where PEA is phenethylammoniu and MA is methylammonium) were report. Compared to 3D MAPbI3 thin films, (PEA)2(MA)n-1PbnI3n+1/MAPbI3 2D/3D bilayer thin films not only possess larger crystals, but also exhibit enhanced build-in potentials, suppressed charge carrier recombination, boosted charge carrier transport, and shortened charge carrier extraction time. As a result, perovskite solar cell by (PEA)2(MA)n-1PbnI3n+1/MAPbI3 2D/3D bilayer thin films exhibit 22.13 % power conversion efficiency with dramatically enhanced stability. Moreover, at room temperature, perovskite photodetectors by (PEA)2(MA)n-1PbnI3n+1/MAPbI3 2D/3D bilayer thin films show a photoresponsivity of 1.38 AW-1, and a detectivity of 6.52 × 1014 Jones (1 Jones = 1 cm Hz1/2 W-1), and a linear dynamic range of over 167 dB. In CHAPTER III, the improved device performance of perovskite photovoltaics by one-step self-assembled (PEA)2(MA)79Pb80I241 thin film incorporating with 0.1% Nd3+ were exhibited. Compared with 3D MAPbI3 thin films, (PEA)2(MA)79Pb80I241: Nd3+ thin film not only possess larger crystal, but also shown enhanced build-in potentials, suppressed charge carrier recombination, boosted charge carrier mobility, and shortened charge carrier extraction time. As a result, perovskite solar cell by (PEA)2(MA)79Pb80I241: Nd3+ thin film exhibit 21.66 % power conversion efficiency with extremely improved stability. Perovskite photodetectors by (PEA)2(MA)79Pb80I241: Nd3+ thin film show a photoresponsivity of 0.83 AW-1, and a detectivity of 4.29 × 1014 Jones (1 Jones = 1 cm Hz1/2 W-1), and a large linear dynamic range over 165 dB. All these results demonstrate that we develop a facile way to realize high-performance and stable perovskite photovoltaics. CHAPTER IV is a summary of two works in terms of perovskite solar cells and perovskite photodetectors. Finally, CHAPTER V is an outlook for future work of perovskite photovoltaics.

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 Defect and Grain Boundary Engineering for Enhanced Performances and Lifetimes of Hybrid Perovskite Solar Cells written by Nicholas Francis DeMarco and published by . This book was released on 2019 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt: As the world energy consumption increases, the necessity for clean energy proves vital and urgent as catastrophic effects of global climate change are imminent. The sun delivers more energy to Earth in just over an hour than we have consumed over the course of last year, making solar technology a most promising candidate for a sustainable future. Currently, state-of-the-art silicon-based solar technologies dominate the market owed to their maturity in processing knowledge, performance reliability, and lifetime. Despite lower costs in recent years, the levelized cost of electricity of silicon-based solar PV technologies is still much greater than conventional fossil fuel sources, providing large incentive to find more cost-effective alternative solar PV technologies. Solution-processed solar technologies are appealing as a low-cost alternative, among which, hybrid perovskites have recently risen as a high performance solution-processed PV technology achieving laboratory scale efficiencies >23%, which are rapidly approaching those of conventional Si-based PV (~26%). However, owed to the solution-processed nature of perovskites, there are many associated defects and grain boundary regions that can adversely affect performances and lifetimes. In this dissertation, I will focus on addressing defect and grain boundary engineering, taking advantage of the wet chemical environment of perovskite thin film processing to manipulate crystallization dynamics and modulate defect and grain boundary properties. In Chapter 4, the guanidinium molecule was first discovered for use in hybrid perovskites. It was found that inclusion of guanidinium can provide extraordinary enhancements in photoluminescent properties of the thin film and enhanced open-circuit voltage of the devices. Based on further experimental analyses and results, we believe that the guanidinium ion serves to suppress formation of defects via lattice strain relaxation and also may serve as a passivant at grain boundaries, giving rise to these impressive improvements. This work opened the door to future works throughout my Ph.D. to control crystallization and defect properties. To further investigate the nature of controlling crystal growth and associated defect natures, a Lewis acid-base adduct approach was developed and is discussed in Chapter 5. The strength of interactios between the Lewis acid perovskite precursors and Lewis base additives were shown to greatly influence nucleation and growth dynamics. The Lewis base urea was found to provide great enhancement in crystal growth, producing larger sized grains and enhanced photoluminescent properties, alongside a greater performance and stability of the device. Lastly, in Chapter 6, the intrinsic stability of the perovskite thin film is addressed by utilizing the compositional and dimensional tenability of hybrid perovskite materials, utilizing a hybrid 3- and 2-dimensionality of the perovskite structure to lead to even further enhanced performances and long-term lifetimes. It was found that the 2-D perovskite forms around grains (at grain boundaries) to facilitate the production of high quality 3-D grains and serve as passivating layers to grain boundaries. These works provide important future directions for hybrid perovskite PV research to realize commercial technologies with competitive efficiencies, long lifetimes, and low costs. Conclusions and future outlooks of these works are discussed in Chapter 7.

Download or read book Perovskite Photovoltaics written by Aparna Thankappan and published by Academic Press. This book was released on 2018-06-29 with total page 521 pages. Available in PDF, EPUB and Kindle. Book excerpt: Perovskite Photovoltaics: Basic to Advanced Concepts and Implementation examines the emergence of perovskite photovoltaics, associated challenges and opportunities, and how to achieve broader development. Consolidating developments in perovskite photovoltaics, including recent progress solar cells, this text also highlights advances and the research necessary for sustaining energy. Addressing different photovoltaics fields with tailored content for what makes perovskite solar cells suitable, and including commercialization examples of large-scale perovskite solar technology. The book also contains a detailed analysis of the implementation and economic viability of perovskite solar cells, highlighting what photovoltaic devices need to be generated by low cost, non-toxic, earth abundant materials using environmentally scalable processes. This book is a valuable resource engineers, scientists and researchers, and all those who wish to broaden their knowledge on flexible perovskite solar cells. Includes contributions by leading solar cell academics, industrialists, researchers and institutions across the globe Addresses different photovoltaics fields with tailored content for what makes perovskite solar cells different Provides commercialization examples of large-scale perovskite solar technology, giving users detailed analysis on the implementation, technical challenges and economic viability of perovskite solar cells

Download or read book Perovskite Photovoltaics and Optoelectronics written by Tsutomu Miyasaka and published by John Wiley & Sons. This book was released on 2022-03-21 with total page 484 pages. Available in PDF, EPUB and Kindle. Book excerpt: Perovskite Photovoltaics and Optoelectronics Discover a one-of-a-kind treatment of perovskite photovoltaics In less than a decade, the photovoltaics of organic-inorganic halide perovskite materials has surpassed the efficiency of semiconductor compounds like CdTe and CIGS in solar cells. In Perovskite Photovoltaics and Optoelectronics: From Fundamentals to Advanced Applications, distinguished engineer Dr. Tsutomu Miyasaka delivers a comprehensive exploration of foundational and advanced topics regarding halide perovskites. It summarizes the latest information and discussion in the field, from fundamental theory and materials to critical device applications. With contributions by top scientists working in the perovskite community, the accomplished editor has compiled a resource of central importance for researchers working on perovskite related materials and devices. This edited volume includes coverage of new materials and their commercial and market potential in areas like perovskite solar cells, perovskite light-emitting diodes (LEDs), and perovskite-based photodetectors. It also includes: A thorough introduction to halide perovskite materials, their synthesis, and dimension control Comprehensive explorations of the photovoltaics of halide perovskites and their historical background Practical discussions of solid-state photophysics and carrier transfer mechanisms in halide perovskite semiconductors In-depth examinations of multi-cation anion-based high efficiency perovskite solar cells Perfect for materials scientists, crystallization physicists, surface chemists, and solid-state physicists, Perovskite Photovoltaics and Optoelectronics: From Fundamentals to Advanced Applications is also an indispensable resource for solid state chemists and device/electronics engineers.

Download or read book Perovskite Solar Cells written by Shahzada Ahmad and published by John Wiley & Sons. This book was released on 2022-03-14 with total page 580 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presents a thorough overview of perovskite research, written by leaders in the field of photovoltaics The use of perovskite-structured materials to produce high-efficiency solar cells is a subject of growing interest for academic researchers and industry professionals alike. Due to their excellent light absorption, longevity, and charge-carrier properties, perovskite solar cells show great promise as a low-cost, industry-scalable alternative to conventional photovoltaic cells. Perovskite Solar Cells: Materials, Processes, and Devices provides an up-to-date overview of the current state of perovskite solar cell research. Addressing the key areas in the rapidly growing field, this comprehensive volume covers novel materials, advanced theory, modelling and simulation, device physics, new processes, and the critical issue of solar cell stability. Contributions by an international panel of researchers highlight both the opportunities and challenges related to perovskite solar cells while offering detailed insights on topics such as the photon recycling processes, interfacial properties, and charge transfer principles of perovskite-based devices. Examines new compositions, hole and electron transport materials, lead-free materials, and 2D and 3D materials Covers interface modelling techniques, methods for modelling in two and three dimensions, and developments beyond Shockley-Queisser Theory Discusses new fabrication processes such as slot-die coating, roll processing, and vacuum sublimation Describes the device physics of perovskite solar cells, including recombination kinetics and optical absorption Explores innovative approaches to increase the light conversion efficiency of photovoltaic cells Perovskite Solar Cells: Materials, Processes, and Devices is essential reading for all those in the photovoltaic community, including materials scientists, surface physicists, surface chemists, solid state physicists, solid state chemists, and electrical engineers.

Download or read book Solar Cells written by Ahmed Mourtada Elseman and published by BoD – Books on Demand. This book was released on 2021-09-22 with total page 489 pages. Available in PDF, EPUB and Kindle. Book excerpt: Solar cell energy is the single most pressing issue facing humanity, with a more technologically advanced society requiring better energy resources. This book discusses technologies broadly, depending on how they capture and distribute solar energy or convert it into solar power. The major areas covered in this book are: • The theory of solar cells, which explains the conversion of light energy in photons into electric current. The theoretical studies are practical because they predict the fundamental limits of a solar cell. • The design and development of thin-film technology-based solar cells. • State of the art for bulk material applied for solar cells based on crystalline silicon (c-Si), also known as “solar grade silicon,” and emerging photovoltaics.

Download or read book Developing Highly Efficient Lead Halide Perovskite Solar Cells written by Jason Jungwan Yoo and published by . This book was released on 2020 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lead halide perovskite solar cells are an emerging technology that can be solution processed to yield low-cost, light weight and flexible photovoltaics. Much of the early work has been focused on developing device structures and processing techniques to improve light absorption and eliminate detrimental traps within the bulk of the perovskite active layer. As a result, the device efficiency of perovskite solar cells has improved from ~3% up to ~20% in less than a decade. However, the device efficiency of perovskite solar cells still need to be much improved in order to compete with traditional photovoltaic technologies, such as Silicon and GaAs, and to ultimately realize the theoretically determined Shockley-Queisser (SQ) efficiency limit. In this thesis, I focus on the development of a novel interface passivation strategy called selective precursor dissolution (SPD) strategy, that utilizes low dimensional 2D perovskites as the interface passivating layer. The post treatment of the bulk perovskite thin film with 2D perovskites via SPD strategy prevented formation of a detrimental non-perovskite phase at the interface and resulted in much improved thin film quality with reduced detrimental interface recombination. As a result, a certified power conversion efficiency (PCE) of 22.6% is achieved from a quasi steady-state measurement along with an electroluminescence (EL) efficiency up to ~9%. Both device metrics were the highest values reported at the time of publication. In addition to developing an interface passivation strategy to improve device performance, a high quality electron transport layer (ETL) was developed and a new perovskite composition was adopted to further improve the device performance. A chemical bath deposition (CBD) was used for the synthesis of a tin dioxide (SnO2) ETL. The pH of the reaction solution is identified as the key parameter for the CBD of SnO2 that controls the quality of the SnO2 ETL. pH 1.5 is determined to be the optimum acidity that results in a SnO2 ETL with compact and conformal coverage without producing a detrimental secondary crystal phase. To improve the optoelectronic properties of the perovskite active layer, MAPbBr3 is significantly reduced to minimize the band gap penalty, which also resulted in improved effective carrier mobility. MAPbBr3 is commonly added to the perovskite composition to stabilize the [alpha]-phase FAPbI3 but results in an increase in the band gap. Addition of 0.8 mol% of MAPbBr3 to the FAPbI3 perovskite resulted in much improved carrier lifetime and effective mobility, compared to conventionally added 10 mol%. Together with the new SnO2 and the perovskite active layer, a record setting and certified PCE of 25.2% is achieved, which translates to 80.5% of the SQ limit for its band gap. In addition, due to low open-circuit voltage (V[subscript OC]) loss, the newly developed devices exhibit an EL efficiency up to 17.2% and an EL wall-plug efficiency up to 21.6%. Both PCE and the EL efficiency is the highest reported so far from a single perovskite solar cell structure.

Download or read book Handbook of Materials Science Volume 1 written by Raghumani S. Ningthoujam and published by Springer Nature. This book was released on 2023-11-21 with total page 759 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents the state-of-the-art coverage of optical materials and their application in various areas. The contents range from basic principles to quantum cutting luminescent materials, advances in plasmonic and photonic substrate-coupled fluorescence, lanthanide doped materials for optical applications, thermoluminescence and optical material for sensing radioactive elements. It also discusses synthesis, characterization and properties of optical materials including nanomaterials, luminescent nanomaterials for anti-counterfeiting, carbon materials-based nanoscale optics and plasmonics, optoelectronics applications of two dimensional materials and applications of lanthanide ion-doped phosphors. This book is of immense value to those in academia and industry working in the areas of material science, especially optical materials.

Download or read book Characterization Techniques for Perovskite Solar Cell Materials written by Meysam Pazoki and published by Elsevier. This book was released on 2019-11-14 with total page 278 pages. Available in PDF, EPUB and Kindle. Book excerpt: Characterization Techniques for Perovskite Solar Cell Materials: Characterization of Recently Emerged Perovskite Solar Cell Materials to Provide an Understanding of the Fundamental Physics on the Nano Scale and Optimize the Operation of the Device Towards Stable and Low-Cost Photovoltaic Technology explores the characterization of nanocrystals of the perovskite film, related interfaces, and the overall impacts of these properties on device efficiency. Included is a collection of both main and research techniques for perovskite solar cells. For the first time, readers will have a complete reference of different characterization techniques, all housed in a work written by highly experienced experts. Explores various characterization techniques for perovskite solar cells and discusses both their strengths and weaknesses Discusses material synthesis and device fabrication of perovskite solar cells Includes a comparison throughout the work on how to distinguish one perovskite solar cell from another

Download or read book Atomic and Nano Scale Materials for Advanced Energy Conversion 2 Volumes written by Zongyou Yin and published by John Wiley & Sons. This book was released on 2022-04-18 with total page 887 pages. Available in PDF, EPUB and Kindle. Book excerpt: Atomic and Nano Scale Materials for Advanced Energy Conversion Discover the latest advancements in energy conversion technologies used to develop modern sustainable energy techniques In Atomic and Nano Scale Materials for Advanced Energy Conversion, expert interdisciplinary researcher Dr. Zongyou Yin delivers a comprehensive overview of nano-to-atomic scale materials science, the development of advanced electrochemical, photochemical, photoelectrochemical, and photovoltaic energy conversion strategies, and the applications for sustainable water splitting and other technologies. The book offers readers cutting-edge information of two-dimensional nano, mixed-dimensional nano, nano rare earth, clusters, and single atoms. It constructively evaluates emerging nano-to-atomic scale energy conversion technologies for academic research and development (R&D) researchers and industrial technique consultants and engineers. The author sets out a systematic analysis of recent energy-conversion science, covering topics like adaptable manufacturing of Van der Waals heterojunctions, mixed-dimensional junctions, tandem structures, and superlattices. He also discusses function-oriented engineering in polymorphic phases, photon absorption, excitons-charges conversion, non-noble plasmonics, and solid-liquid-gas interactions. Readers will also benefit from: A thorough introduction to emerging nanomaterials for energy conversion, including electrochemical, photochemical, photoelectrochemical, and photovoltaic energy conversion An exploration of clusters for energy conversion, including electrochemical, photochemical, and photoelectrochemical clusters Practical discussions of single atoms for energy conversion in electrochemical, photochemical, and photoelectrochemical energy conversion technologies A thorough analysis of future perspectives and directions in advanced energy conversion technology Perfect for materials scientists, photochemists, electrochemists, and inorganic chemists, Atomic and Nano Scale Materials for Advanced Energy Conversion is also a must-read resource for catalytic chemists interested in the intersection of advanced chemistry and physics in energy conversion technologies.

Download or read book Hybrid Perovskite Solar Cells written by Hiroyuki Fujiwara and published by John Wiley & Sons. This book was released on 2022-01-10 with total page 612 pages. Available in PDF, EPUB and Kindle. Book excerpt: Unparalleled coverage of the most vibrant research field in photovoltaics! Hybrid perovskites, revolutionary game-changing semiconductor materials, have every favorable optoelectronic characteristic necessary for realizing high efficiency solar cells. The remarkable features of hybrid perovskite photovoltaics, such as superior material properties, easy material fabrication by solution-based processing, large-area device fabrication by an inkjet technology, and simple solar cell structures, have brought enormous attentions, leading to a rapid development of the solar cell technology at a pace never before seen in solar cell history. Hybrid Perovskite Solar Cells: Characteristics and Operation covers extensive topics of hybrid perovskite solar cells, providing easy-to-read descriptions for the fundamental characteristics of unique hybrid perovskite materials (Part I) as well as the principles and applications of hybrid perovskite solar cells (Part II). Both basic and advanced concepts of hybrid perovskite devices are treated thoroughly in this book; in particular, explanatory descriptions for general physical and chemical aspects of hybrid perovskite photovoltaics are included to provide fundamental understanding. This comprehensive book is highly suitable for graduate school students and researchers who are not familiar with hybrid perovskite materials and devices, allowing the accumulation of the accurate knowledge from the basic to the advanced levels.

Download or read book Industrial Organic Pigments written by Willy Herbst and published by John Wiley & Sons. This book was released on 2006-03-06 with total page 678 pages. Available in PDF, EPUB and Kindle. Book excerpt: 'Everything there is to know about organic pigments' Revised and updated, this highly acclaimed work, now in its third edition, remains the most comprehensive source of information available on synthetic organic pigments. The book provides up-to-date information on synthesis, reaction mechanisms, physical and chemical properties, test methods, and applications of all industrially produced organic pigments of the world market. Standardized methods have been used to obtain the data thus facilitating comparison between pigments. Chemists, engineers, colorists, and technicians are sure to find this book invaluable. 'Presentation throughout is of the highest quality and the volume must now become the standard reference text in this important area of colouring matters.' Dyes and Pigments 'This is a very wide-ranging reference work ... it would be difficult to find a topic in this field not covered by this book.' Ecochem

Download or read book Printable Solar Cells written by Nurdan Demirci Sankir and published by John Wiley & Sons. This book was released on 2017-04-19 with total page 578 pages. Available in PDF, EPUB and Kindle. Book excerpt: Printable Solar Cells The book brings together the recent advances, new and cutting edge materials from solution process and manufacturing techniques that are the key to making photovoltaic devices more efficient and inexpensive. Printable Solar Cells provides an overall view of the new and highly promising materials and thin film deposition techniques for printable solar cell applications. The book is organized in four parts. Organic and inorganic hybrid materials and solar cell manufacturing techniques are covered in Part I. Part II is devoted to organic materials and processing technologies like spray coating. This part also demonstrates the key features of the interface engineering for the printable organic solar cells. The main focus of Part III is the perovskite solar cells, which is a new and promising family of the photovoltaic applications. Finally, inorganic materials and solution based thin film formation methods using these materials for printable solar cell application is discussed in Part IV. Audience The book will be of interest to a multidisciplinary group of fields, in industry and academia, including physics, chemistry, materials science, biochemical engineering, optoelectronic information, photovoltaic and renewable energy engineering, electrical engineering, mechanical and manufacturing engineering.

Download or read book Solution processed Fabrication of Hybrid Organic inorganic Perovskites Back Interface Engineering of Cadmium Telluride Solar Cells written by Suneth C. Watthage and published by . This book was released on 2017 with total page 179 pages. Available in PDF, EPUB and Kindle. Book excerpt: Thin film solar cells based on hybrid organic-inorganic perovskites (HOIPs) have become highly attractive over the past several years due to a high solar to electric power conversion efficiencies (PCEs). Perovskite materials based on methylammonium lead iodide (CH3NH3PbI3, MAPbI3) possess high optical absorption coefficients, long minority carrier lifetimes and diffusion lengths, and desirable optical band gaps, and carrier collection in these materials can be highly efficient when they are paired with appropriate electron and hole transport materials (ETMs and HTMs), respectively. Additionally, perovskite solar cells (PSCs) can be fabricated via a variety of solution-based routes, which are suitable for low-cost, large area manufacturing. The combination of these attributes gives PSCs an advantage over currently available commercial photovoltaic (PV) technologies. Understanding the nucleation and growth mechanisms, and controlling the grain size and crystallinity in the solution-processed fabrication of perovskite thin films are important to prepare electronic-quality materials for PV applications. We investigated the nucleation and growth mechanisms of MAPbI3 formed in a two-step solution process. To prepare the MAPbI3 films, PbI2 films were spin-coated and then were reacted with methylammonium iodide (MAI) in the isopropanol (IPA) solution at various concentrations. We showed that the conversion rate, grain size, and morphology of MAPbI3 perovskite films depend on the concentration of the MAI solution. Three distinct perovskite formation behaviors were observed at various MAI concentrations, and a tentative model was proposed to explain the reaction mechanisms. The nucleation and growth process of MAPbI3 can be significantly changed by adding divalent metal salts into the MAI solution. We showed that the incorporation of Cd2+ ions significantly improved the grain size, crystallinity, and photoexcited carrier lifetime of MAPbI3. Formation of (CH3NH3)2CdI4 (MA2CdI4) perovskite in the solution by reacting the MAI and Cd2+ is the key for this nucleation and growth change. Devices prepared using this approach showed a significant improvement in the PCE relative to control devices prepared without Cd2+ addition. The improved optoelectronic properties are attributed to a Cd-modified film growth mechanism that invokes low dimensional Cd-based perovskites. In addition to the Cd2+, Zn2+ and Fe2+ also have the potential to change the nucleation and growth process of MAPbI3 formation, to improve the material quality. Formation of Cd-based perovskites, once the Cd2+ ions contacted with MAI, successfully applied in the cadmium telluride (CdTe) solar cell technology to form a Te layer on the CdTe surface, that would reduce the Schottky barrier height and band bending at the back contact, reducing the recombination at the back junction, and thus improve the device efficiency. We found that Cd can be selectively extracted from the CdTe surface by reacting MAI thin films with the CdTe surface, forming MA2CdI4 perovskite. MA2CdI4 is soluble in IPA, therefore can be rinsed out, leaving a Te layer behind on the CdTe surface. MAI treated CdTe devices showed a reduction in the barrier height at the back contact for both Au and transparent indium tin oxide (ITO) electrodes as calculated from the temperature dependent J-V measurements, resulting higher photovoltaic parameters of open circuit voltage (VOC), fill factor (FF), and PCE relative to the control devices. In addition, only a ~6% reduction in transmittance in the near infrared (NIR) region occurred in the devices with an ITO back electrode due to the MAI treatment, indicating this can be potentially used for the fabrication of high performance transparent CdTe solar cells that use in tandem solar cell or window applications.

Download or read book Perovskite Materials Devices and Integration written by He Tian and published by BoD – Books on Demand. This book was released on 2020-06-10 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt: Perovskites have attracted great attention in the fields of energy storage, pollutant degradation as well as optoelectronic devices due to their excellent properties. This kind of material can be divided into two categories; inorganic perovskite represented by perovskite oxide and organic-inorganic hybrid perovskite, which have described the recent advancement separately in terms of catalysis and photoelectron applications. This book systematically illustrates the crystal structures, physic-chemical properties, fabrication process, and perovskite-related devices. In a word, perovskite has broad application prospects. However, the current challenges cannot be ignored, such as toxicity and stability.