Download or read book Development of Highly Efficient and Stable Lead free Perovskite Solar Cells Through Composition and Interface Engineering written by Gabriella A. Tosado and published by . This book was released on 2020 with total page 193 pages. Available in PDF, EPUB and Kindle. Book excerpt: Solar energy has the highest capacity to power our energy needs sustainably without emitting greenhouse gases. Hybrid organic-inorganic lead halide perovskite solar cells (PVSCs) have emerged in the past decade as a promising low-cost, low energy intensity, thin film solar cell with lab efficiencies reaching 25.2%. The toxicity of Pb perovskites and performance and stability issues with Sn lead-free alternatives remains a major roadblock to commercialization. In this work, novel perovskite compositions are designed and used to study the transition from Pb to Sn perovskites, cations are tuning to implement stabilizing components for pure Sn perovskites, and Sn perovskites performance and stability issues are tackled. The triple cation methylammonium (MA), formamidinium (FA) and Cs, with double halide composition Csx(MA0.17FA0.83)1-xPb1-ySny(I0.83Br0.17)3 films with x = 0.05, 0.10, and 0.20 and y = 0, 0.25, 0.50, 0.75, and 1.0 was used to create a library of new perovskites and study novel band gap trends near the maximum Schockley Quiesser limit. The simple inverted device structure of indium tin oxide (ITO)/poly (3,4, -ethylenedioxythiphene): polystyrene sulfonate (PEDOT:PSS)/Perovskite/[6,6]-phenyl-C60-butyric acid methyl ester (PC60BM)/fullerene (C60)/2,9-dimethyl-7,7-diphenyl-1,10-phenanthroline (BCP)/Ag eliminated dopant instabilities. Due to a high-quality film morphology and optimal bandgap, 3 3 Cs0.05(MA0.17FA0.83)0.95Pb0.25Sn0.75(I0.83Br0.17)3 (band gap = 1.30 eV), achieved a record maximum efficiency of 11.05% for any 75% Sn composition. Moreover, the 75% Sn PVSCs retained 80% of initial PCE after 30 days storage in inert conditions and 100 hours in ambient conditions. After optimizing antisolvent choice, solvent annealing, and hot casting conditions for pure Sn perovskite films, the novel composition with Cs, FA, and guanidinium (GA), (CsGA)xFA100 2xSnI3 was implemented. This cation mixture combines the benefits of a guanidinium cation, such as increased hydrogen bonding and no dipole moment, with Cs to fill point defects and relax the crystal lattice to better integrate a large stabilizing agent, ethylenediammonium diiodide (EDAI2). The EDAI2 additive not only yielded pinhole-free cubic phase (CsGA)xFA100-2xSnI3 perovskite films but also decreased both shallow and deep trap states in the perovskite films. The devices with (CsGA)15FA70SnI3 and 0-2% EDAI2 all achieved a maximum PCE higher than 5% with the highest of 5.72% for a fresh device with (CsGA)15FA70SnI3 and 1% EDAI2. After storage, the maximum PCE was increased from 5.69% to 6.39% for the (CsGA)15FA70SnI3 and 1.5% EDAI2 devices. Finally, to tackle energy loss issues that have plagued pure Sn perovskites (loss = 0.6-0.9 V), the misalignment between the PEDOT:PSS hole transport layer and the Sn perovskite valence band was studied due to the energy misalignment between the hole transport layer and pure Sn perovskite valence band. Cosolvent methods, solvent wash methods, and solvent immersion methods with DMSO, EG, and CH3OH were implemented to alter the PSS content and work function of the HTL to improve alignment. Utilizing the (CsGA)15FA70SnI3+1.0% EDAI2 perovskite film we demonstrated a higher performance of 6.29% and 6.16% with a 5% DMSO cosolvent and methanol solvent wash, respectively. This work is a comprehensive push to improve the performance and stability of non-toxic Sn perovskite devices, bringing this technology one step closer to commercialization.

Download or read book Nanomaterials for Green Energy written by Bharat A. Bhanvase and published by Elsevier. This book was released on 2018-04-18 with total page 502 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nanomaterials for Green Energy focuses on the synthesis, characterization and application of novel nanomaterials in the fields of green science and technology. This book contains fundamental information about the properties of novel nanomaterials and their application in green energy. In particular, synthesis and characterization of novel nanomaterials, their application in solar and fuel cells and batteries, and nanomaterials for a low-toxicity environment are discussed. It will provide an important reference resource for researchers in materials science and renewable energy who wish to learn more about how nanomaterials are used to create cheaper, more efficient green energy products. Provides fundamental information about the properties and application of new low-cost nanomaterials for green energy Shows how novel nanomaterials are used to create more efficient solar cells Offers solutions to common problems related to the use of materials in the development of energy- related technologies

Download or read book Composition and Interface Engineering for Stable and Highly Efficient Wide Bandgap Perovskite Solar Cells written by 劉田田 and published by . This book was released on 2020 with total page 121 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Interface Engineering and Morphology Study of Thin Film Organic Inorganic Halide Perovskite Optoelectronic Devices written by Lei Meng and published by . This book was released on 2017 with total page 161 pages. Available in PDF, EPUB and Kindle. Book excerpt: Solar energy harvesting through photovoltaic conversion has gained great attention as a sustainable and environmentally friendly solution to meet the rapidly increasing global energy demand. Currently, the high cost of solar-cell technology limits its widespread use. This situation has generated considerable interest in developing alternative solar-cell technologies that reduce cost through the use of less expensive materials and processes. Perovskite solar cells provide a promising low-cost technology for harnessing this energy source. In Chapter two, a moisture-assist method is introduced and studied to facilitate grain growth of solution processed perovskite films. As an approach to achieve high-quality perovskite films, I anneal the precursor film in a humid environment (ambient air) to dramatically increase grain size, carrier mobility, and charge carrier lifetime, thus improving electrical and optical properties and enhancing photovoltaic performance. It is revealed that mild moisture has a positive effect on perovskite film formation, demonstrating perovskite solar cells with 17.1% power conversion efficiency. Later on, in Chapter four, an ultrathin flexible device delivering a PCE of 14.0% is introduced. The device is based on silver-mesh substrates exhibiting superior durability against mechanical bending. Due to their low energy of formation, organic lead iodide perovskites are also susceptible to degradation in moisture and air. The charge transport layer therefore plays a key role in protecting the perovskite photoactive layer from exposure to such environments, thus achieving highly stable perovskite-based photovoltaic cells. Although incorporating organic charge transport layers can provide high efficiencies and reduced hysteresis, concerns remain regarding device stability and the cost of fabrication. In this work, perovskite solar cells that have all solution-processed metal oxide charge transport layers were demonstrated. Stability has been significantly improved compared with cells made with organic layers. Degradation mechanisms were investigated and important guidelines were derived for future device design with a view to achieving both highly efficient and stable solar devices. Organometal halide based perovskite material has great optoelectronic proprieties, for example, shallow traps, benign grain boundaries and high diffusion length. The perovskite LEDs show pure electroluminescence (EL) with narrow full width at half maximum (FWHM), which is an advantage for display, lighting or lasing applications. In chapter five, perovskite LEDs are demonstrated employing solution processed charge injection layers with a quantum efficiency of 1.16% with a very low driving voltage.

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 High Quality Perovskite Films for Efficient and Stable Light Emitting Diodes written by Heyong Wang and published by Linköping University Electronic Press. This book was released on 2020-09-15 with total page 61 pages. Available in PDF, EPUB and Kindle. Book excerpt: Metal halide perovskites have attracted significant attention for light-emitting applications, because of their excellent properties, such as high photoluminescence quantum yields (PLQYs), good charge mobility, narrow emission bandwidth, readily tunable emission spectra ranging from ultraviolet to near-infrared, and solution processability. Since the first room-temperature perovskite-based light-emitting diodes (PeLEDs) reported in 2014, tremendous efforts have been made to promote the efficiencies of PeLEDs, including theoretical simulation, materials design, and device engineering. To reach the ultimate goal of commercialization, PeLEDs with both high-efficiency and long-term operational stability are desired. Achieving high-quality perovskite emissive films is key towards this goal. Centering around the high-quality perovskite films, in this thesis, we demonstrate effective synthesis strategies for the deposition of high-quality perovskite films (including both three-dimensional and mixed-dimensional perovskites) and investigate the effects of ion migration in the perovskite films on the performance of PeLEDs. Due to the fast crystallization nature of perovskites and the low formation energy of defects, controlling the crystallization processes of these films has proved to be an effective approach for achieving high-quality perovskite films. For three-dimensional (3D) perovskite films, we have controlled the formation of these films through the assistance of molecules with the amino group. Herein, we have chosen an electron-transport molecule with two amino groups, 4,4’-diaminodiphenyl sulfone (DDS), to control the crystallization process of perovskite films (Paper 1). The resulting perovskite films consists of in-situ formed high quality perovskite nanocrystals embedded in the electron-transport molecular matrix, resulting in improved PLQYs and structural stability. PeLEDs based on these perovskite films have exhibited both high efficiency and long operational stability. In addition, we have investigated the formation of mixed-dimensional perovskite films. Efficient PeLEDs based on mixed-dimensional perovskite films were fabricated with tin dioxide (SnO2) as an electron transport layer (Paper 3). We also note that the deposition methods have a significant impact on the morphology and optical properties of prepared mixed-dimensional perovskite films (Paper 4). In addition, we provide an effective method to extend the deposition of mixed-dimensional perovskite films, replacing organic ammonium halides with amines in the perovskite precursor solutions to form organic spacer cations through the in-situ protonation process of amines (Paper 2). In spite of these efforts, the performance of PeLEDs is still far from the commercialization standard, partially limited by ion migration. In Paper 5, we discuss impacts of mobile ions in the perovskite films on the performance of PeLEDs. We find that a dynamic redistribution of mobile ions can change current density of a device, leading to EQE/hysteresis during forward and reverse voltage scan and enhanced EQE under constant driving voltages. In addition, we have found that excess mobile ions in the perovskite layer can aggravate the hysteresis and shorten the operational stability of PeLEDs. In this thesis, we also discuss the remaining key challenges in the PeLED field, including the achievement of high-performance blue, white, and lead-free PeLEDs, as well as possible strategies to address these challenges. We hope that our research findings provide insights into the basic science behind the perovskite materials, and broadly benefit other optoelectronic communities, such as perovskite solar cells, flexible electronics, and so on. Metall-halid-perovskiter har fått mycket uppmärksamhet för deras möjlighet att användas i ljusemitterande applikationer på grund utav utmärkta egenskaper så som högt fotoluminiscent kvantutbyte (PLQYs), god mobilitet, smalt emissionsband, lättjusterat emissionsspektra i intervallet ultraviolett till nära infrarött, samt för att de kan beredas med en lösningsbaserad process. Ända sedan de första perovskitbaserade ljusdioderna (PeLEDs) som verkande i rumstemperatur rapporterades 2014 har enormt arbete lagts ner på att öka effektiviteten hos PeLEDs, till exempel genom teoretiska simuleringar, materialdesign och teknisk utformning utav lysdioden. För att nå det slutgiltiga målet med kommersialisering behövs PeLEDs som har både hög effektivitet och driftstabilitet. Att uppnå högkvalitativa emitterande perovskitfilmer är nyckeln för att nå detta mål. I den här avhandlingen, vilken fokuserar på högkvalitativa perovskitfilmer, demonstrerar vi effektiva syntetiseringsstrategier för deponering utav högkvalitativa perovskitfilmer och undersöker effekterna jonmigration har på prestandan i perovskitfilmerna i PeLEDs. På grund utav den snabbkristalliserande naturen hos perovskitfilmer och den låga bildningsenergin för defekter så har kontroll utav kristallisationsprocessen av dessa filmer visat sig vara en effektiv väg för att uppnå högkvalitativa perovskitfilmer. När det gäller tredimensionella perovskitfilmer så har vi kontrollerat bildandet av dessa filmer genom assistans från molekyler med aminogrupper. Vi har valt en elektrontransporterande molekyl som har två aminogrupper, 4,4’- diaminodifenyl sulfon (DDS), för att kontrollera kristallisationsprocessen av perovskitfilmer (artikel 1). De beredda perovskitfilmerna bestod av insitu- bildade högkvalitativa perovskitnanokristaller inbäddade i en elektrontransporterande molekylär matris vilket resulterade i förbättrat fotoluminiscent-kvantutbyte och strukturell stabilitet. PeLEDs baserade på dessa perovskitfilmer har uppvisat både hög effektivitet och lång driftstabilitet. Därtill har vi undersökt bildandet av blanddimensionella perovskiter. Effektiva PeLEDs baserade på blanddimensionella perovskiter var tillverkade med tenndioxid (SnO2) som elektrontransportlager (artikel 3). Vi noterade även att val av deponeringsmetod hade signifikant effekt på IV morfologi och optiska egenskaper av de beredda blanddimensionella perovskitfilmerna (artikel 4). Därutöver tillhandahöll vi en effektiv metod för att deponera blanddimensionella perovskitfilmer genom att ersätta de vanligen använda organiska ammoniumhaliderna med aminer i prekursorlösningen för att bilda organiska distansierande katjonfilmer genom en in-situ-protoneringsprocess av aminer (artikel 2). Även om PeLEDs med högkvalitativa perovskitfilmer har visat förbättrad effektivitet och driftstabilitet så uppvisar lysdioderna fortfarande egenskaper som associeras med jonmigration. I artikel 5 diskuterar vi effekten av mobila joner i perovskitfilmer och hur de påverkar PeLEDs prestanda. Vi fann att den dynamiska omfördelningen av mobila joner i perovskitskiktet kan ändra det elektriska nettofältet i perovskitskiktet, modifiera laddningsbärarnas rekombination i perovskitskiktet och leda till ostadig strömdensitet. Dessutom har vi funnit att överskott av mobila joner i perovskitskiktet är en av de största anledningarna till den korta driftstabiliteten för PeLEDs. I denna avhandling diskuterar vi även kvarstående nyckelproblem i PeLED-fältet så som bedriften att uppnå högpresterande blå, vita och blyfria PeLEDs så väl som möjliga strategier att möta dessa utmaningar. Våra forskningsresultat ger insikter om den grundläggande vetenskapen bakom perovskitmaterialen vilka vi tror kommer vara till stort gagn för andra optoelektroniska fält, så som perovskitsolceller, flexibel elektronik och så vidare.

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 Efficient Stable Perovskite Solar Cells Enabled by Electrode Interface Engineering and Nanoscale Phase Stabilization written by Erin M. Sanehira and published by . This book was released on 2017 with total page 135 pages. Available in PDF, EPUB and Kindle. Book excerpt: Semiconducting metal halide perovskites have emerged as a promising solution-processable, photovoltaic material with research cell power conversion efficiencies now exceeding 22% under simulated sunlight. The prototypical composition of this “ABX3” semiconductor is CH3NH3PbI3, in which organic methylammonium cations charge stabilize lead iodide octahedra. Research is underway on mixed component systems with A-site cation combinations of methylammonium, formamidinium, cesium, and rubidium; B-site cations of Pb2+ and Sn2+; and iodide, bromide and chloride anions. Although perovskite solar cells with low-cost fabrication methods have demonstrated impressive power conversion efficiencies, device durability remains a key concern of the technology. In this dissertation, the effect of the anode electrode material on the device lifetime is characterized under constant operating conditions. It is demonstrated that MoOx/Al electrodes are more stable than commonly used Au or Ag electrodes. Interestingly, the enhanced stability of MoOx/Al electrodes is due to the formation of an oxide at the MoOx/Al interface, which likely prevents ion migration between the device layers, as opposed to encapsulation from environmental agents. I also demonstrate a more stable photoactive layer comprised of CsPbI3 quantum dots (QDs). CsPbI3 is the lowest bandgap, all-inorganic lead halide perovskite, and has shown remarkable chemical and thermal stability up to 400 °C. However, bulk and thin film CsPbI3 transitions to the undesired orthorhombic phase when cooled to room temperature. CsPbI3 QDs have unique surface properties which alter the phase transitions and successfully maintain the photoactive cubic phase at room temperature and even well below. In addition to reporting the first demonstration of an all-inorganic CsPbX3 nanocrystal solar cell, I also detail new QD surface treatments that improve the short circuit current density of the devices by doubling the QD film mobility. These advancements led to an NREL-certified QD solar cell efficiency of 13.43% that is currently the record efficiency reported for a QD solar cell of any material system. In this dissertation, I assess operational stability of thin film organic-inorganic perovskite solar cells, fabricate more durable electrodes, develop novel CsPbI3 QD photovoltaic devices and discover new surface modifications to improve charge transport in efficient perovskite QD solar cells.

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 Development of Solar Cells written by Juganta K. Roy and published by Springer Nature. This book was released on 2021-05-12 with total page 235 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents a comprehensive overview of the fundamental concept, design, working protocols, and diverse photo-chemicals aspects of different solar cell systems with promising prospects, using computational and experimental techniques. It presents and demonstrates the art of designing and developing various solar cell systems through practical examples. Compared to most existing books in the market, which usually analyze existing solar cell approaches this volume provides a more comprehensive view on the field. Thus, it offers an in-depth discussion of the basic concepts of solar cell design and their development, leading to higher power conversion efficiencies. The book will appeal to readers who are interested in both fundamental and application-oriented research while it will also be an excellent tool for graduates, researchers, and professionals working in the field of photovoltaics and solar cell systems.

Download or read book High Efficiency and Stable Carbon Based Planar Perovskite Solar Cells written by Vijayaraghavan Sankaranarayanan Nair and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Perovskite solar cells (PSCs) have attracted much attention both in research and industrial domains. The power conversion efficiencies (PCE) of PSCs have been improved from 3.8% to 25.8% in just over a decade, rivaling that of silicon solar cells. Hybrid perovskite materials have exceptional optoelectrical properties and can be processed using cost-effective solution-based methods. In contrast, the fabrication of silicon solar cells requires high-vacuum, high-temperature, and energy-intensive processes. The combination of excellent optoelectrical properties and cost-effective manufacturing makes hybrid perovskite a winning candidate for solar cells.As the PCE of PSCs improves and their long-term stability increases, one of the crucial hurdles to be addressed is the cost-effective scalable fabrication and its long-term stability. Most high-efficiency solar cells require an energy-consuming method of depositing the cathode to complete the cell. These high-efficiency devices also require highly expensive noble metal electrodes. Herein, following recommendations from the literature, carbon-based nanomaterials are utilized, and their effects on the efficiency, fill factor (FF), open-circuit voltage (Voc), and short circuit density (Jsc) are analyzed. The PSCs and carbon counter electrodes are fabricated at low temperatures (~100 degrees Celsius). As per the literature, carbon-based devices exhibited an efficiency of >19%. This endeavor further buttresses the fact that carbon nanomaterials are promising candidates for the future of low-cost, high-performance, and scalable production of PSCs. Thus, complex vacuum deposition of expensive cathodes to complete the cells might be eliminated.In this thesis, I focus on several novel interface engineering techniques, that can reduce the surface roughness of the carbon electrode, and improve the interface it forms with the underlying layer. These interfacial engineering techniques improved the charge collection efficiency of the carbon, and thereby reduced the recombination happening at the interface. As a result, the PCE could be enhanced from ~13% to >18%.In addition to these techniques, a high-quality narrow band gap perovskite layer was developed with low dimensional 2D perovskite passivation to further improve the device performance. Together with the improved perovskite film quality and optimized film composition, along with interface engineered carbon electrode, an impressive PCE of >21% was attained.

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 238 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 High performance Perovskite Solar Cells by Active Layer Composition Engineering written by Lening Shen and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the past 10 years, perovskite solar cells (PSCs) have drawn great attention in both academic and industrial sectors. Over 25.5% power conversion efficiency (PCE) has been reported from PSCs by three-dimensional (3D) methylammonium lead iodide (CH3NH3PbI3 or MAPbI3). However, the previous studies have indicated that PSCs exhibited poor stability. Thus, to commercialize PSCs, the development of efficient and stable PSCs is required. In this study, we reported two approaches to develop efficient and stable PSCs. One was to develop novel all-inorganic perovskites, where Pb2+ was partially heterovalently substituted Nd3+. Another was to develop PSCs with a bulk heterojunction (BHJ) device structure. In the first approach, it was found that the CsPbI2Br:xNd3+ thin films possess enhanced charge carrier mobilities, superior crystallinity, and enlarged crystal sizes, but with enlarged optical bandgaps. As a result, PSCs by the CsPbI2Br:xNd3+ thin films exhibit more than 20% enhanced PCEs and boosted stability compared to those by pristine CsPbI2Br thin film. To further boost the device performance of PSCs, solution-processed 4-lithium styrenesulfonic acid/styrene copolymer (LiSPS) is utilized as the passivation layer. PSCs by the CsPbI2Br:xNd3+/LiSPS bilayer thin film possesses reduced charge extraction lifetime and suppressed charge carrier recombination, resulting in 17.05% PCE and dramatically boosted stability compared to that without the LiSPS passivation layer. All these results indicate that we develop a facile way to approach high-performance PSCs by all-inorganic perovskite materials. In the second approach, we found that all-inorganic perovskite incorporated with low bandgap conjugated polymers, forming BHJ composite thin film possesses balanced and enhanced charge mobilities, superior film morphology with enlarged crystal sizes, and suppressed trap density As a result, BHJ PSCs exhibited a 21.08% PCEs, which is more than 16% enhancement compared to that without incorporated with low bandgap conjugated polymers. Moreover, BHJ PSCs possess suppressed photocurrent hysteresis and enhanced device stability. All these results demonstrate that the development of BHJ PSCs is one of the facil ways to approach high-performance PSCs.

Download or read book Printable Mesoscopic Perovskite Solar Cells written by Hongwei Han and published by John Wiley & Sons. This book was released on 2023-06-07 with total page 309 pages. Available in PDF, EPUB and Kindle. Book excerpt: Printable Mesoscopic Perovskite Solar Cells A comprehensive exploration of printable perovskite solar cells and their potential for commercialization In Printable Mesoscopic Perovskite Solar Cells, a team of distinguished researchers delivers an accessible and incisive discussion of the principles, technologies, and fabrication processes associated with the manufacture and use of perovskite solar cells. The authors detail the properties, characterization methods, and technologies for halide perovskite materials and devices and explain printable processing technologies, mesoscopic anode and cathodes, and spacer layers for printable perovskite solar cells. In the book, you’ll find expansive discussions of the stability issues inherent in perovskite solar cells and explore the potential for scaling and commercializing the printing of perovskite solar cells, complete with real-world industry data. Readers will also find: A thorough introduction to the background and fundamentals of perovskite solar cells Comprehensive explorations of the characterization methods and technologies used with halide perovskite materials and devices Practical discussions of printable processing technologies for perovskite solar cells Fulsome treatments of the stability issues associated with perovskite solar cells and potential solutions for them Perfect for materials scientists, solid state physicists and chemists, and electronics engineers, Printable Mesoscopic Perovskite Solar Cells will also benefit surface chemists and physicists.

Download or read book Towards High Efficiency and Stable Metal Halide Perovskite Solar Cells written by Yepin Zhao and published by . This book was released on 2021 with total page 169 pages. Available in PDF, EPUB and Kindle. Book excerpt: Metal halide perovskite solar cells have proven themselves as one of the most promising candidates to replace the currently well-commercialized silicon-based solar cells. Because of its unique energy band structure, it has merits such as high defect tolerance, favorable charge carrier mobility, and high absorption coefficient. However, the major issue that hinders the successful real-life application of the metal halide perovskite solar cell is its unsatisfactory stability. In Chapter One, I introduce the four basic elements that cause the instability of perovskite solar cells: light, heat, bias, and moisture. The perovskite material degradation mechanism behind each environment will be detailly illustrated. Ion migration suppression and device encapsulation can be regarded as the main solutions to enhance the operational lifetime of the perovskite solar cells. From interior to exterior, in the following chapters, I introduce the strategies we developed that are proven to be powerful to improve the stability of the metal halide perovskite solar cells.In Chapter Two, I introduce the first strategy of interior multivalent interstitial doping. It is a strategy originated inside the perovskite lattice. Cations with suitable sizes to occupy an interstitial site of perovskite crystals have been widely used to inhibit ion migration and promote the performance and stability of perovskite optoelectronics. However, the interstitial doping accompanies inevitable lattice strain to impair the long-range ordering and stability of the crystals to cause a sacrificial trade-off. In this chapter, I unravel the evident influence of the valence states of the interstitial cations on their efficacy to suppress the ion migration. Incorporation of a trivalent neodymium cation (Nd3+) effectively mitigates the ion migration in the perovskite lattice with a significantly reduced dosage (0.08%) compared to a widely used monovalent cation dopant (Na+, 0.45%). Less but better, the prototypical perovskite solar cells incorporated with Nd3+ exhibits significantly enhanced photovoltaic performance and operational stability. In Chapter Three, I discuss the defect passivation of the perovskite crystal, which constitutes one of the most commonly used strategies to fabricate highly efficient perovskite solar cells (PSCs). The durability of the passivation effects under harsh operational conditions has not been extensively studied regardless of the weak and vulnerable secondary bonding between the molecular passivation agents and perovskite crystals. Here, we incorporated strategically designed passivating agents to investigate the effect of their interaction energies with the perovskite crystals and correlated these with the performance and longevity of the passivation effects. We unraveled that the passivation agents with a stronger interaction energy are advantageous not only for effective defect passivation, but also to suppress defect migration. The prototypical PSCs treated with the optimal passivation agent exhibited superior performance and operational stability, retaining 81.9% and 85.3% of their initial performance under continuous illumination or nitrogen at 85 °C after 1008 hours, respectively while the reference device completely degraded during the time. This work provides important insights into designing operationally durable defect passivation agents for perovskite optoelectronic devices. In Chapter Four, we focus on the perovskite grain and the grain boundary density. Intrinsically, detrimental defects accumulating at the surface and grain boundaries limit both the performance and stability of perovskite solar cells. Small molecules and bulkier polymers with functional groups are utilized to passivate these ionic defects but usually suffer from volatility and precipitation issues, respectively. Starting from the addition of small monomers in PbI2 precursor, in this chapter, I introduce a polymerization-assisted grain growth (PAGG) strategy in the sequentially deposited method. With a polymerization process triggered during the PbI2 film annealing, the bulkier polymers formed will be adhered to the grain boundaries, remaining the previously established interactions with PbI2. After perovskite formation, the polymers anchored on the boundaries can effectively passivate under-coordinated lead ions and reduce defect density. As a result, we obtain a champion power conversion efficiency (PCE) of 23.0%, together with a prolonged lifetime where 85.7% and 91.8% of the initial PCE remains after 504-hour continuous illumination and 2208-hour shelf storage, respectively. In Chapter Five, I will go to the exterior of the perovskite solar cell and introduce a novel strategy of device encapsulation. Unstable nature against moisture is one of the major issues of metallic halide perovskite solar cell application. Thin-film encapsulation is known as a powerful approach to notably enhance the operational stability of perovskite solar cells in a humid environment. However, encapsulation layers with ideal gas barrier performance always require harsh fabrication conditions with high temperature and harmful precursors. For this reason, here we provide a mild encapsulation strategy to maintain the original performance of solar cell devices by utilization of ethylene glycol-induced immediate layer to minimize the damage of plasma-enhanced atomic layer deposition to perovskite solar cells. The organic-inorganic alternating encapsulation structure has exhibited a water vapor transmittance rate of 1.3 10-5 g m-2 day-1, which is the lowest value among the reported thin-film encapsulation layers of perovskite solar cells. Our perovskite solar cells have survived at 80% relative humidity and 30 C for over 2000 hours while preserving 96% of their initial performance.

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 Machine Learning and Computer Vision for Renewable Energy written by Acharjya, Pinaki Pratim and published by IGI Global. This book was released on 2024-05-01 with total page 351 pages. Available in PDF, EPUB and Kindle. Book excerpt: As the world grapples with the urgent need for sustainable energy solutions, the limitations of traditional approaches to renewable energy forecasting become increasingly evident. The demand for more accurate predictions in net load forecasting, line loss predictions, and the seamless integration of hybrid solar and battery storage systems is more critical than ever. In response to this challenge, advanced Artificial Intelligence (AI) techniques are emerging as a solution, promising to revolutionize the renewable energy landscape. Machine Learning and Computer Vision for Renewable Energy presents a deep exploration of AI modeling, analysis, performance prediction, and control approaches dedicated to overcoming the pressing issues in renewable energy systems. Transitioning from the complexities of energy prediction to the promise of advanced technology, the book sets its sights on the game-changing potential of computer vision (CV) in the realm of renewable energy. Amidst the struggle to enhance sustainability across industries, CV technology emerges as a powerful ally, collecting invaluable data from digital photos and videos. This data proves instrumental in achieving better energy management, predicting factors affecting renewable energy, and optimizing overall sustainability. Readers, including researchers, academicians, and students, will find themselves immersed in a comprehensive understanding of the AI approaches and CV methodologies that hold the key to resolving the challenges faced by renewable energy systems.