Query: BAckground of perovskite

Candidate papers:

abstract: The photovoltaics of organic inorganic lead halide perovskite materials have shown rapid improvements in solar cell performance, surpassing the top efficiency of semiconductor compounds such as CdTe and CIGS (copper indium gallium selenide) used in solar cells in just about a decade. Perovskite preparation via simple and inexpensive solution processes demonstrates the immense potential of this thin film solar cell technology to become a low cost alternative to the presently commercially available photovoltaic technologies. Significant developments in almost all aspects of perovskite solar cells and discoveries of some fascinating properties of such hybrid perovskites have been made recently. This Review describes the fundamentals, recent research progress, present status, and our views on future prospects of perovskite based photovoltaics, with discussions focused on strategies to improve both intrinsic and extrinsic (environmental) stabilities of high efficiency devices. Strategies and challenges regarding compositional engineering of the hybrid perovskite structure are discussed, including potentials for developing all inorganic and lead free perovskite materials. Looking at the latest cutting edge research, the prospects for perovskite based photovoltaic and optoelectronic devices, including non photovoltaic applications such as X ray detectors and image sensing devices in industrialization, are described. In addition to the aforementioned major topics, we also review, as a background, our encounter with perovskite materials for the first solar cell application, which should inspire young researchers in chemistry and physics to identify and work on challenging interdisciplinary research problems through exchanges between academia and industry.
author_names: Ajay Kumar Jena

Ashish Kulkarni

Tsutomu Miyasaka
title: Halide Perovskite Photovoltaics: Background, Status, and Future Prospects.
venue: Chemical reviews
year: 2019

abstract: Abstract In a physical vapor deposition process for fabrication of perovskite absorber layers it is an important prerequisite for large scale application to understand the reaction steps and the impact of the deposition parameters on the structural and compositional characteristics of vacuum deposited lead halide perovskite layers. In the sequential deposition method, we found a narrow and low lying temperature window for the transformation of a vapor deposited PbCl2 base layer to CH3NH3PbI3 perovskite by reaction with evaporated CH3NH3I. To modify the deposition parameter window, we systematically varied background pressure and substrate temperature and analyzed the resulting composition using X ray diffraction, energy dispersive X ray spectroscopy, and scanning electron microscopy. The resulting reaction products and byproducts CH3NH3PbI3, CH3NH3PbCl3, PbICl, PbCl2, and PbI2 were identified and the variation of their concentration in dependence of background pressure and substrate temperature is explained by discussion of a set of reaction equations and reaction mechanisms on a thermodynamic basis.
author_names: Carolin Wittich

Eric Mankel

Oliver Clemens

K Lakus-Wollny

Thomas Mayer

Wolfram Jaegermann

Hans Joachim Kleebe
title: Structural and compositional characteristics of vacuum deposited methylammonium lead halide perovskite layers in dependence on background pressure and substrate temperature
year: 2018

abstract: In Sn based halide perovskite solar cells (PSCs) the oxidation of Sn2+ to Sn4+ under ambient air leads to unwanted p type doping in the perovskite film, which is a main reason for increased background carrier density and low efficiency. Here, we find that the introduction of bromide into formamidinium tin iodide (CH(NH2)2SnI3, FASnI3) lattice significantly lowers the carrier density of perovskite absorber, which is thought to be a result of reduction of Sn vacancies. It reduces the leakage current of devices, increases recombination lifetime, and finally improves open circuit voltage and fill factor of the resulting devices employing mesoporous TiO2 as an electron transport layer. Consequently, a high power conversion efficiency (PCE) of 5.5% is achieved with an average PCE of 5% and after encapsulation the devices are highly stable over 1000 h under continuous one sun illumination including the ultraviolet region. This study suggests a simple approach for improving stability and efficiency in FASnI3 ba.
author_names: Seon Joo Lee

Seong Sik Shin

Jino Im

Tae Kyu Ahn

Jun Hong Noh

Nam Joong Jeon

Sang Il Seok

Jangwon Seo
title: Reducing Carrier Density in Formamidinium Tin Perovskites and Its Beneficial Effects on Stability and Efficiency of Perovskite Solar Cells
year: 2018

abstract: Abstract Perovskites are a kind of important materials used in the electronic system, information storage and energy utilization, etc. This chapter provides a brief background on perovskite materials. The typical synthesis strategies, driven by the demanding of the compositional engineering, are introduced. Due to the broad tolerance factors, compositional engineering is useful to tailor the origin structure and elemental compositions in perovskites by various synthesis methods, such as the solid state reaction, wet chemical methods, and the hydrothermal synthesis method. The sol gel method, as an important wet chemical synthesis technology, plays a key role in the doping of abundant ions and realizing of various phase/grain interfaces. BiFeO3 based and bismuth layered perovskites are thoroughly expounded in terms of compositional engineering.
author_names: Hua Ke
title: Compositional engineering of perovskite materials
year: 2021

abstract: Over the past decade, intensive research efforts have been directed toward the field of organic inorganic hybrid perovskites, with dramatic progress made in both the photovoltaic performance and device stability. Therefore, it has become the fastest growing photovoltaic research area. Perovskite materials use low cost earth abundant elements and can be solution processed; furthermore, the technology is compatible with large scale roll to roll manufacturing. Recently, the successful demonstration of the photovoltaic performance of perovskites reaching that of the commercialized monosilicon photovoltaic technology combined with the significantly improved stability has made scaling up the perovskite PV technology to become a new research area, which is the topic of this review. First, the fundamental background knowledge of classical nucleation and crystal growth from a solution is summarized along with its application in perovskite film evolution. We then discuss the common perovskite PV device architectures and perovskite layer deposition methods, followed by summarizing scalable solution approaches with recent progress and related challenges for the scaling up process. Upon the introduction of the current in depth understanding of perovskite nucleation and crystal growth, external strategies (including both physical and chemical approaches) controlling the perovskite film formation are reviewed in diverse scalable manufacturing methods. Overall, aiming at overcoming the challenges of transferring from laboratory research, we provide an overview of achieving high performance perovskite solar cells by using scalable fabrication methods via precise nucleation and crystal growth control during the perovskite film formation process.
author_names: Hanlin Hu

Mriganka Singh

Xuejuan Wan

Jiao-ning Tang

Chih-Wei Chu

Gang Li
title: Nucleation and crystal growth control for scalable solution processed organic inorganic hybrid perovskite solar cells
year: 2020

abstract: Lead free tin halide perovskite solar cells (PSCs) have attracted great attention because of their low toxicity, ideal band gap, and high carrier mobilities. However, the efficiency and reproducibility of tin halide PSCs has been limited because of the facile oxidation of Sn2+ to Sn4+ Herein, liquid formic acid (LFA) was introduced as a reducing solvent in the FASnI3 (FA: formamidinium) perovskite precursor solution. Unlike solid reducing additives, the LFA solvent is volatile, so no residual LFA remained in the FASnI3 perovskite film. Use of the LFA solvent resulted in production of the FASnI3 perovskite film with high crystallinity, low Sn4+ content, reduced background doping, and low electronic trap density. As a result, an efficiency of over 10% was obtained for lead free tin halide PSCs with improved reproducibility.
author_names: Xiangyue Meng

Tianhao Wu

Xiao Liu

Xin He

Takeshi Noda

Yanbo Wang

Hiroshi Segawa

Liyuan Han
title: Highly Reproducible and Efficient FASnI3 Perovskite Solar Cells Fabricated with Volatilizable Reducing Solvent.
venue: The journal of physical chemistry letters
year: 2020

abstract: Over the last several years, inorganic organic hybrid perovskites have shown dramatic achievements in photovoltaic performance and device stability. Despite the significant progress in photovoltaic application, an in depth understanding of the fundamentals of precursor solution chemistry is still lacking. In this review, the fundamental background knowledge of nucleation and crystal growth processes in solution including the LaMer model and Ostwald ripening process is described. This review article also highlights the recent progress in precursor coordinating molecule interaction in solution along with the role of anti solvent in the solvent engineering process to control nucleation and crystal growth. Moreover, chemical pathways from precursor solution to perovskite film formation are given. This represents identification of the intermediate phase induced by precursor coordinating molecule interaction and responsible intermediate species for uniform and dense perovskite film formation. Further to the description of chemical phenomena in solution, the contemporary progress in chemical precursor composition is also provided to comprehend the current research approaches to further enhance photovoltaic performance and device stability. On the basis of the critical and comprehensive review, we provide some perspectives to further achieve high performance perovskite solar cells with long term device stability through precisely controlled nucleation and crystal growth in precursor solution.
author_names: Minsu Jung

Sang-Geun Ji

Gwisu Kim

Sang Il Seok
title: Perovskite precursor solution chemistry: from fundamentals to photovoltaic applications.
venue: Chemical Society reviews
year: 2019

abstract: The road ahead for perovskites The high power conversion efficiencies of small area perovskite solar cells (PSCs) have driven interest in the development of commercial devices. Rong et al. review recent progress in addressing stability, how to allow mass production, and how to maintain uniformity of large area films. They note that lifetimes exceeding 10,000 hours under 1 sun (1 kW/m2) illumination have been reported for printable triple mesoscopic PSCs. Science, this issue p. eaat8235 BACKGROUND Perovskite solar cells (PSCs) have attracted intensive attention because of their ever increasing power conversion efficiency (PCE) low cost materials constituents, and simple solution fabrication process. Initiated in 2009 with an efficiency of 3.8% PSCs have now achieved a lab scale power conversion efficiency of 23.3% rivaling the performance of commercial multicrystalline silicon solar cells, as well as copper indium gallium selenide (CIGS) and cadmium telluride (CdTe) thin film solar cells. Thousands of articles related to PSCs have been published each year since 2015, highlighting PSCs as a topic of intense interest in photovoltaics (PV) research. With high efficiencies achieved in lab devices, stability and remaining challenges in upscaling the manufacture of PSCs are two critical concerns that must be addressed on the path to PSC commercialization. ADVANCES We review recent progress in PSCs and discuss the remaining challenges along the pathway to their commercialization. Device configurations of PSCs (see the figure) include mesoscopic formal (n i p) and inverted (p i n) structures, planar formal and inverted structures, and the printable triple mesoscopic structures. PCEs of devices that use these structures have advanced rapidly in the case of small area devices ~0.1 cm2) PSCs are also attracting attention as top cells for the construction of tandem solar cells with existing mature PV technologies to increase efficiency beyond the Shockley Queisser limit of single junction devices. The stability of PSCs has attracted much well deserved attention of late, and notable progress has been made in the past few years. PSCs have recently achieved exhibited lifetimes of 10,000 hours under 1 sun (1 kW/m2) illumination with an ultraviolet filter at a stabilized temperature of 55degC and at short circuit conditions for a printable triple mesoscopic PSCs. This irradiation is equivalent to the total irradiation of 10 years of outdoor use in most of Europe. However, within the PSC community, standard testing protocols require further development. In addition, transparency in reporting standards on stability tests needs to be improved; this can be achieved by providing both initial photovoltaic performance and normalization parameters. The upscaling of PSCs has also progressed steadily, leading to PSC mini modules, standard sized modules, and power systems. PV companies have set out to manufacture large area PSC modules (see the figure) and a 110 m2 perovskite PV system with screen printed triple mesoscopic PSC modules was recently debuted. Studies of these increased area modules and systems will promote the development of PSCs toward commercialization. PSC research is expanding to cover fundamental topics on materials and lab sized cells, as well as to address issues of industrial scale manufacturing and deployment. OUTLOOK The PV market has been continuously expanding in recent years, bringing opportunities for new PV technologies of which PSCs are promising candidates. It is imperative to achieve a low cost per watt, which means that both efficiency and lifetime need improvement relative to current parameters. The efficiency gap between lab cells and industrial modules has seen impressive reductions in crystalline silicon; PSCs must similarly enlarge module areas to the panel level and need to achieve lifetimes comparable to those of legacy PV technologies. Other improvements will need to include industry scale electronic grade films, recycling methods to address concerns regarding lead toxicity, and the adoption of standardized testing protocols to predict the operation lifetime of PSCs. Modules will need to endure light induced degradation, potential induced degradation, partial shade stress, and mechanical shock. The field can benefit from lessons learned during the development of mature PV technologies as it strives to define, and overcome, the hurdles to PSC commercial impact. Configurations and application demonstration of PSCs. PSCs have been developed in various device configurations, including mesoscopic, planar, triple mesoscopic, and tandem structures. Recently, a 110 m2 perovskite PV system with printable triple mesoscopic PSC modules (3600 cm2 for each) was launched by WonderSolar in China. PHOTO: WONDERSOLAR Perovskite solar cells (PSCs) have witnessed rapidly rising power conversion efficiencies, together with advances in stability and upscaling. Despite these advances, their limited stability and need to prove upscaling remain crucial hurdles on the path to commercialization. We summarize recent advances toward commercially viable PSCs and discuss challenges that remain. We expound the development of standardized protocols to distinguish intrinsic and extrinsic degradation factors in perovskites. We review accelerated aging tests in both cells and modules and discuss the prediction of lifetimes on the basis of degradation kinetics. Mature photovoltaic solutions, which have demonstrated excellent long term stability in field applications, offer the perovskite community valuable insights into clearing the hurdles to commercialization.
author_names: Yaoguang Rong

Yue Hu

Anyi Mei

Hairen Tan

Makhsud I Saidaminov

Sang Il Seok

Michael D McGehee

Edward H Sargent

Hongwei Han
title: Challenges for commercializing perovskite solar cells
venue: Science
year: 2018

abstract: The low power conversion efficiency (PCE) of tin based hybrid perovskite solar cells (HPSCs) is mainly attributed to the high background carrier density due to a high density of intrinsic defects such as Sn vacancies and oxidized species (Sn4+ that characterize Sn based HPSCs. Herein, this study reports on the successful reduction of the background carrier density by more than one order of magnitude by depositing near single crystalline formamidinium tin iodide (FASnI3) films with the orthorhombic a axis in the out of plane direction. Using these highly crystalline films, obtained by mixing a very small amount (0.08 m) of layered (2D) Sn perovskite with 0.92 m (3D) FASnI3, for the first time a PCE as high as 9.0% in a planar p i n device structure is achieved. These devices display negligible hysteresis and light soaking, as they benefit from very low trap assisted recombination, low shunt losses, and more efficient charge collection. This represents a 50% improvement in PCE compared to the best reference cell based on a pure FASnI3 film using SnF2 as a reducing agent. Moreover, the 2D/3D based HPSCs show considerable improved stability due to the enhanced robustness of the perovskite film compared to the reference cell.
author_names: Shuyan Shao

Jian Liu

Giuseppe Portale

Hong-Hua Fang

Graeme R Blake

Gert H ten Brink

L Jan Anton Koster

Maria Antonietta Loi
title: Highly Reproducible Sn Based Hybrid Perovskite Solar Cells with 9% Efficiency
year: 2018

abstract: Abstract The unknown LSMO/ZnO spin orbit dynamics and bandgap are presented by Mn partial wave state density of LaSrMnO3 and SRS spectroscopy. Raman active phonon in orthorhombic perovskite ZnO/La0.7Sr0.3MnO films are were focused by measuring Raman spectra in various scattering configurations. The LSMO spin state density is modified by Mn mixed valence state. The results show that the spin orbit is caused by anomalies tilt of MnO6 octahedron and electrons hopped into the empty orbital states. The transfer of d x 2 y 2 orbits dynamics is in the background of the ferro orbital order state of crystal stabilized d 3 z 2 r 2 orbit effect. The LSMO/ZnO displays magnetic and phononic scattering measurement. The kinetic energy gain achieved by the orbital competition, magnetic ordering, strong crystal field and charge order of energy band splitting. The LSMO/ZnO junction exhibits excellent junction antiferromagnetic/ferromagnetic phonon peaks and magnetoresistance behavior over the temperature range of 77 300 K. The significant energy band competition originates from the strong crystal splitting field and orbital canting.
author_names: Ren Ren

Yijing Ren

Xuan Li

Lei Bai
title: Carrier transport spin orbit dynamics in surface enhanced Raman shift of perovskite films
year: 2016