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1.
The field of halide metal perovskite photovoltaics has caught widespread interest in the last decade. This is seen in the rapid rise of power conversion efficiency, which is currently over 23%. It has also stimulated a widespread application of halide metal perovskites in other fields, such as light‐emitting diodes, field‐effect transistors, detectors, and lasers. Despite the fascinating characteristics of the halide metal perovskites, the presence of toxic lead (Pb) in their chemical composition is regarded as one of the major limiting factors preventing their commercialization. Addressing the toxicity issues in these compounds by a careful and strategic replacement of Pb2+ with other nontoxic candidate elements represents a promising direction to fabricate lead‐free optoelectronic devices. Such attempts yield a halide double perovskite structure which allows flexibility for various compositional adjustments. Here, the authors present the current progress and setbacks in crystal structures, materials preparation, optoelectronic properties, stability, and photovoltaic applications of lead‐free halide double perovskite compounds. Prospective research directions to improve the optoelectronic properties of existing materials are given that may help in the discovery of new lead‐free halide double perovskites. 相似文献
2.
Zhanhao Hu Zonghao Liu Luis K. Ono Maowei Jiang Sisi He Dae‐Yong Son Yabing Qi 《Liver Transplantation》2020,10(24)
Solar cells based on metal halide perovskites have emerged as a promising low‐cost photovoltaic technology. In contrast to inert atmospheres where most of the lab‐scale devices are made to date, large‐area low‐cost production of perovskite solar cells often involves processing of perovskites in various atmospheres including ambient air, nitrogen, and/or vacuum. Herein, the impact of atmosphere on the energy levels of methylammonium lead halide perovskite films is systematically investigated. The atmosphere is varied to simulate the typical fabrication process. Through a comprehensive analysis combining the Fermi level evolution, surface photovoltage, photoluminescence properties, photovoltaic performance, and device simulation, an overall landscape of the energy diagram of the perovskite layer is able to be determined. The findings have direct implications for real‐world devices under typical atmospheres, and provide insights into the fabrication‐process design and optimization. Furthermore, a universal Fermi level shift under vacuum for lead halide‐based perovskites revealed in this study, urges a refreshed view on the energetics studies conducted without considering the atmospheric effect. 相似文献
3.
Andreas J. Bornschlegl Michael F. Lichtenegger Leo Luber Carola Lampe Maryna I. Bodnarchuk Maksym V. Kovalenko Alexander S. Urban 《Liver Transplantation》2024,14(10):2303312
Semiconductor nanocrystals can replace conventional bulk materials completely in displays and light-emitting diodes. Exciton transport dominates over charge carrier transport for materials with high exciton binding energies and long ligands, such as halide perovskite nanocrystal films. Here, how beneficial superlattices – nearly perfect 3D assemblies of nanocrystals - are to exciton transport is investigated. Surprisingly, the high degree of order is not as crucial as the individual nanocrystal size, which strongly influences the splitting of the excitonic manifold into bright and dark states. At very low temperatures, the energetic splitting is larger for the smallest nanocrystals, and dark levels with low oscillator strength effectively trap excitons inside individual nanocrystals, suppressing diffusion. The effect is reversed at elevated temperatures, and the larger nanocrystal size becomes detrimental to exciton transport due to enhanced exciton trapping and dissociation. The results reveal that the nanocrystal size must be strongly accounted for in design strategies of future optoelectronic applications. 相似文献
4.
The Importance of Pendant Groups on Triphenylamine‐Based Hole Transport Materials for Obtaining Perovskite Solar Cells with over 20% Efficiency 
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下载免费PDF全文 Jinbao Zhang Bo Xu Li Yang Changqing Ruan Linqin Wang Peng Liu Wei Zhang Nick Vlachopoulos Lars Kloo Gerrit Boschloo Licheng Sun Anders Hagfeldt Erik M. J. Johansson 《Liver Transplantation》2018,8(2)
Tremendous progress has recently been achieved in the field of perovskite solar cells (PSCs) as evidenced by impressive power conversion efficiencies (PCEs); but the high PCEs of >20% in PSCs has so far been mostly achieved by using the hole transport material (HTM) spiro‐OMeTAD; however, the relatively low conductivity and high cost of spiro‐OMeTAD significantly limit its potential use in large‐scale applications. In this work, two new organic molecules with spiro[fluorene‐9,9′‐xanthene] (SFX)‐based pendant groups, X26 and X36, have been developed as HTMs. Both X26 and X36 present facile syntheses with high yields. It is found that the introduced SFX pendant groups in triphenylamine‐based molecules show significant influence on the conductivity, energy levels, and thin‐film surface morphology. The use of X26 as HTM in PSCs yields a remarkable PCE of 20.2%. In addition, the X26‐based devices show impressive stability maintaining a high PCE of 18.8% after 5 months of aging in controlled (20%) humidity in the dark. We believe that X26 with high device PCEs of >20% and simple synthesis show a great promise for future application in PSCs, and that it represents a useful design platform for designing new charge transport materials for optoelectronic applications. 相似文献
5.
Olga Malinkiewicz Cristina Roldán‐Carmona Alejandra Soriano Enrico Bandiello Luis Camacho Mohammad Khaja Nazeeruddin Henk J. Bolink 《Liver Transplantation》2014,4(15)
Metal‐oxide‐free methylammonium lead iodide perovskite‐based solar cells are prepared using a dual‐source thermal evaporation method. This method leads to high quality reproducible films with large crystal domain sizes allowing for an in depth study of the effect of perovskite film thickness and the nature of the electron and hole blocking layers on the device performance. The power conversion efficiency increases from 4.7% for a device with only an organic electron blocking layer to almost 15% when an organic hole blocking layer is also employed. In addition to the in depth study on small area cells, larger area cells (approx. 1 cm?2) are prepared and exhibit efficiencies in excess of 10%. 相似文献
6.
Wen‐Fan Yang Femi Igbari Yan‐Hui Lou Zhao‐Kui Wang Liang‐Sheng Liao 《Liver Transplantation》2020,10(13)
The chemical composition engineering of lead halide perovskites via a partial or complete replacement of toxic Pb with tin has been widely reported as a feasible process due to the suitable ionic radius of Sn and its possibility of existing in the +2 state. Interestingly, a complete replacement narrows the bandgap while a partial replacement gives an anomalous phenomenon involving a further narrowing of bandgap relative to the pure Pb and Sn halide perovskite compounds. Unfortunately, the merits of this anomalous behavior have not been properly harnessed. Although promising progress has been made to advance the properties and performance of Sn‐based perovskite systems, their photovoltaic (PV) parameters are still significantly inferior to those of the Pb‐based analogs. This review summarizes the current progress and challenges in the preparation, morphological and photophysical properties of Sn‐based halide perovskites, and how these affect their PV performance. Although it can be argued that the Pb halide perovskite systems may remain the most sought after technology in the field of thin film perovskite PV, prospective research directions are suggested to advance the properties of Sn halide perovskite materials for improved device performance. 相似文献
7.
Sofia Masi Aurora Rizzo Rahim Munir Andrea Listorti Antonella Giuri Carola Esposito Corcione Neil D. Treat Giuseppe Gigli Aram Amassian Natalie Stingelin Silvia Colella 《Liver Transplantation》2017,7(14)
Low‐molecular‐weight organic gelators are widely used to influence the solidification of polymers, with applications ranging from packaging items, food containers to organic electronic devices, including organic photovoltaics. Here, this concept is extended to hybrid halide perovskite‐based materials. In situ time‐resolved grazing incidence wide‐angle X‐ray scattering measurements performed during spin coating reveal that organic gelators beneficially influence the nucleation and growth of the perovskite precursor phase. This can be exploited for the fabrication of planar n‐i‐p heterojunction devices with MAPbI3 (MA = CH3NH3+) that display a performance that not only is enhanced by ≈ 25% compared to solar cells where the active layer is produced without the use of a gelator but that also features a higher stability to moisture and a reduced hysteresis. Most importantly, the presented approach is straightforward and simple, and it provides a general method to render the film formation of hybrid perovskites more reliable and robust, analogous to the control that is afforded by these additives in the processing of commodity “plastics.” 相似文献
8.
Kai Wang Yuchen Hou Bed Poudel Dong Yang Yuanyuan Jiang Min‐Gyu Kang Ke Wang Congcong Wu Shashank Priya 《Liver Transplantation》2019,9(37)
Biomacromolecular pigments, such as melanin, play an essential role in the survival of all living beings. Melanin absorbs sunlight and transforms it into heat, which is crucial for avoiding damage to skin cells. Light absorption produces excited electrons, which could either fall back to ground states by releasing the heat (photothermal effect) and/or light (photoluminescence), or stay at higher energy levels within its lifetime period, which can be captured through external electronic circuitry (photovoltaic effect). In this study, it is demonstrated that the combination of melanin with halide perovskite light absorber in the form of a composite exhibits high absorbance from the UV to NIR region in the solar spectrum. And the composite displays significantly reduced photoluminescence and minimized density of residual excited states (verified by photovoltaic measurement) owing to the significantly enhanced nonradiant quenching by the melanin. As a result, the composite shows an ultrahigh solar‐thermal quantum yield of 99.56% and solar‐thermal conversion efficiency of ≈81% under one‐sun illumination (AM1.5), which is superior to typical carbon materials such as graphene (≈70%). By coating the photothermal composite film on the hot‐side of thermoelectric devices, a 7000% increase in output power as compared to the blank device under illumination is observed. 相似文献
9.
Diego Di Girolamo Nga Phung Felix Utama Kosasih Francesco Di Giacomo Fabio Matteocci Joel A. Smith Marion A. Flatken Hans Kbler Silver H. Turren Cruz Alessandro Mattoni Lucio Cin Bernd Rech Alessandro Latini Giorgio Divitini Caterina Ducati Aldo Di Carlo Danilo Dini Antonio Abate 《Liver Transplantation》2020,10(25)
The operation of halide perovskite optoelectronic devices, including solar cells and LEDs, is strongly influenced by the mobility of ions comprising the crystal structure. This peculiarity is particularly true when considering the long‐term stability of devices. A detailed understanding of the ion migration‐driven degradation pathways is critical to design effective stabilization strategies. Nonetheless, despite substantial research in this first decade of perovskite photovoltaics, the long‐term effects of ion migration remain elusive due to the complex chemistry of lead halide perovskites. By linking materials chemistry to device optoelectronics, this study highlights that electrical bias‐induced perovskite amorphization and phase segregation is a crucial degradation mechanism in planar mixed halide perovskite solar cells. Depending on the biasing potential and the injected charge, halide segregation occurs, forming crystalline iodide‐rich domains, which govern light emission and participate in light absorption and photocurrent generation. Additionally, the loss of crystallinity limits charge collection efficiency and eventually degrades the device performance. 相似文献
10.
This review provides an update on the progress in understanding formation and degradation mechanisms in halide perovskites for photovoltaic applications, as supported by in situ and operando X‐ray scattering techniques. The value of these real‐time analyses is particularly high for gaining insights into the structural evolution during crystal formation and decomposition upon exposure to external stress factors. This type of analysis reveals the pathways between starting and end points of a process rather than being limited to comparing states before and after the process. Special attention is put on the successful efforts toward upscaling including deposition techniques that are compatible to roll‐to‐roll processing. These processes are realized using fast annealing procedures. The development of these processes strongly benefited from in situ studies exploring the direct transition from precursor to perovskite without going through observable crystalline intermediate phases. A particular focus of this review is the benefit of using in situ and operando X‐ray scattering techniques to better understand and ultimately improve device stability. The difference between structural stability of thin films and structural stability under device operation is highlighted, convincingly demonstrating the indispensability of operando studies. 相似文献
11.
Aditya Narayan Singh Sandeep Kajal Junu Kim Atanu Jana Jin Young Kim Kwang S. Kim 《Liver Transplantation》2020,10(30)
Moisture, heat, and light instabilities of halide perovskites (HPs) represent a serious Achilles' heel that must be overcome, to enable future advancements in perovskite‐based optoelectronic devices such as solar cells and light‐emitting diodes. The instabilities are attributed to the unavoidable fragile ionic bonding between cationic and anionic parts of HPs during their formation. Surface passivation of HPs by various surface‐passivating materials has proven to be an attractive approach to stabilize perovskites against moisture, heat, and light, keeping intact their structural integrity and ionic bonding. Herein, the experimental and theoretical background for degradation mechanisms of HPs is reviewed along with various surface passivating materials to stabilize HPs. Finally, the existing challenges associated with thin‐film and device fabrication and an outlook for improving the stability of perovskites in optoelectronics are presented 相似文献
12.
Zhixing Gan Xiaoming Wen Weijian Chen Chunhua Zhou Shuang Yang Guiyuan Cao Kenneth P. Ghiggino Hua Zhang Baohua Jia 《Liver Transplantation》2019,9(20)
Photon recycling and carrier diffusion are the two plausible processes that primarily affect the carrier dynamics in halide perovskites, and therefore the evaluation of the performance of their photovoltaic and photonic devices. However, it is still challenging to isolate their individual contributions because both processes result in a similar emission redshift. Herein, it is confirmed that photon recycling is the dominant effect responsible for the observed redshifted emission. By applying one‐ and two‐photon confocal emission microscopy on Ruddlesden–Popper type 2D perovskites, of which interplane carrier diffusion is strictly suppressed, the substantial PL redshift (72 meV) is well reproduced by the photon transport model. A comparison of 3D bulk CH3NH3PbBr3 single crystal to 2D perovskite by depth‐resolved two‐photon PL spectra reveals the contribution of carrier diffusion on energy transport at a distance beyond diffusion length is constantly negligible, though the carrier diffusion indeed exists in the 3D crystal. The investigation resolves the fundamental confusion and debate surrounding the issue and provides significant insights into carrier kinetics in perovskites, which is important for future developments in solar cells and other optoelectronic devices. 相似文献
13.
14.
Yingxia Zong Zhongmin Zhou Min Chen Nitin P. Padture Yuanyuan Zhou 《Liver Transplantation》2018,8(27)
State‐of‐the‐art perovskite solar cells (PSCs) have bandgaps that are invariably larger than 1.45 eV, which limits their theoretically attainable power conversion efficiency. The emergent mixed‐(Pb, Sn) perovskites with bandgaps of 1.2–1.3 eV are ideal for single‐junction solar cells according to the Shockley–Queisser limit, and they have the potential to deliver higher efficiency. Nevertheless, the high chemical activity of Sn(II) in these perovskites makes it extremely challenging to control their physical properties and chemical stability, thereby leading to PSCs with relatively low PCE and stability. In this work, the authors employ the Lewis‐adduct SnF2·3FACl additive in the solution‐processing of ideal‐bandgap halide perovskites (IBHPs), and prepare uniform large‐grain perovskite thin films containing continuously functionalized grain boundaries with the stable SnF2 phase. Such Sn(II)‐rich grain‐boundary networks significantly enhance the physical properties and chemical stability of the IBHP thin films. Based on this approach, PSCs with an ideal bandgap of 1.3 eV are fabricated with a promising efficiency of 15.8%, as well as enhanced stability. The concept of Lewis‐adduct‐mediated grain‐boundary functionalization in IBHPs presented here points to a new chemical route for approaching the Shockley–Queisser limit in future stable PSCs. 相似文献
15.
Photoluminescence spectroscopy is a widely applied characterization technique for semiconductor materials in general and halide perovskite solar cell materials in particular. It can give direct information on the recombination kinetics and processes as well as the internal electrochemical potential of free charge carriers in single semiconductor layers, layer stacks with transport layers, and complete solar cells. The correct evaluation and interpretation of photoluminescence requires the consideration of proper excitation conditions, calibration and application of the appropriate approximations to the rather complex theory, which includes radiative recombination, non‐radiative recombination, interface recombination, charge transfer, and photon recycling. In this article, an overview is given of the theory and application to specific halide perovskite compositions, illustrating the variables that should be considered when applying photoluminescence analysis in these materials. 相似文献
16.
17.
Tom J. Savenije Dengyang Guo Valentina M. Caselli Eline M. Hutter 《Liver Transplantation》2020,10(26)
The unprecedented rise in the power conversion efficiency of solar cells based on metal halide perovskites (MHPs) has led to enormous research effort to understand their photophysical properties. The progress made in understanding the mobility and recombination of photogenerated charge carriers from nanosecond to microsecond time scales, monitored using electrodeless transient photoconductivity techniques, is reviewed. In addition, a kinetic model to obtain rate constants from transient data recorded using a wide range of laser intensities is presented. For various MHPs the temperature dependence of the mobilities and recombination rates are evaluated. Furthermore, it is shown how these rate constants can be used to predict the upper limit for the open‐circuit voltage Voc of the corresponding device. Finally, the photophysical properties of MHPs that are not yet fully understood are explored, and recommendations for future research directions are made. 相似文献
18.
Lead halide perovskites have recently emerged as promising absorbers for fabricating low‐cost and high‐efficiency thin‐film solar cells. The record power conversion efficiency of lead halide perovskite‐based solar cells has rapidly increased from 3.8% in 2009 to 22.1% in early 2016. Such rapid improvement is attributed to the superior and unique photovoltaic properties of lead halide perovskites, such as the extremely high optical absorption coefficients and super‐long photogenerated carrier lifetimes and diffusion lengths that are not seen in any other polycrystalline thin‐film solar cell materials. In the past a few years, theoretical approaches have been extensively applied to understand the fundamental mechanisms responsible for the superior photovoltaic properties of lead halide perovskites and have gained significant insights. This review article highlights the important theoretical results reported in literature for the understanding of the unique structural, electronic, optical, and defect properties of lead halide perovskite materials. For comparison, we also review the theoretical results reported in literature for some lead‐free perovskites, double perovskites, and nonperovskites. 相似文献
19.
In recent years, there have been remarkable developments in halide perovskites, which are used in highly efficient optoelectronic devices and exhibit intriguing materials physics. Detailed knowledge of carrier recombination mechanisms is essential for understanding their excellent performance and to further increase their efficiency. Obtaining such knowledge is challenging however, and different studies have reached divergent conclusions in some cases. This progress report outlines the critical developments in understanding the carrier recombination mechanisms in halide perovskites from a computational perspective. The primary focus is radiative and Auger recombination, since they have not been systematically assessed and discussed before, and a number of important issues have been actively debated. This comprehensive discussion of the carrier recombination mechanisms is aimed at establishing physically justified insights that can form the basis for better materials and devices design. 相似文献
20.
Wei Chen Yecheng Zhou Guocong Chen Yinghui Wu Bao Tu Fang‐Zhou Liu Li Huang Alan Man Ching Ng Aleksandra B. Djuri&#x;i&#x; Zhubing He 《Liver Transplantation》2019,9(19)
In this work, significant suppression of the interfacial recombination by facile alkali chloride interface modification of the NiOx hole transport layer in inverted planar perovskite solar cells is achieved. Experimental and theoretical results reveal that the alkali chloride interface modification results in improved ordering of the perovskite films, which in turn reduces defect/trap density, causing reduced interfacial recombination. This leads to a significant improvement in the open‐circuit voltage from 1.07 eV for pristine NiOx to 1.15 eV for KCl‐treated NiOx, resulting in a power conversion efficiency approaching 21%. Furthermore, the suppression of the ion diffusion in the devices is observed, as evidenced by stable photoluminescence (PL) under illumination and high PL quantum efficiency with alkali chloride treatment, as opposed to the luminescence enhancement and low PL quantum efficiency observed for perovskite on pristine NiOx. The suppressed ion diffusion is also consistent with improved stability of the devices with KCl‐treated NiOx. Thus, it is demonstrated that a simple interfacial modification is an effective method to not only suppress interfacial recombination but also to suppress ion migration in the layers deposited on the modified interface due to improved interface ordering and reduced defect density. 相似文献