共查询到20条相似文献,搜索用时 15 毫秒
1.
Pengchen Zhu Shuai Gu Xin Luo Yuan Gao Songlin Li Jia Zhu Hairen Tan 《Liver Transplantation》2020,10(3)
The performance of perovskite solar cells is sensitive to detrimental defects, which are prone to accumulate at the interfaces and grain boundaries of bulk perovskite films. Defect passivation at each region will lead to reduced trap density and thus less nonradiative recombination loss. However, it is challenging to passivate defects at both the grain boundaries and the bottom charge transport layer/perovskite interface, mainly due to the solvent incompatibility and complexity in perovskite formation. Here SnO2‐KCl composite electron transport layer (ETL) is utilized in planar perovskite solar cells to simultaneously passivate the defects at the ETL/perovskite interface and the grain boundaries of perovskite film. The K and Cl ions at the ETL/perovskite interface passivate the ETL/perovskite contact. Meanwhile, K ions from the ETL can diffuse through the perovskite film and passivate the grain boundaries. An enhancement of open‐circuit voltage from 1.077 to 1.137 V and a corresponding power conversion efficiency increasing from 20.2% to 22.2% are achieved for the devices using SnO2‐KCl composite ETL. The composite ETL strategy reported herein provides an avenue for defect passivation to further increase the efficiency of perovskite solar cells. 相似文献
2.
Tobias Abzieher Somayeh Moghadamzadeh Fabian Schackmar Helge Eggers Florian Sutterlüti Amjad Farooq Danny Kojda Klaus Habicht Raphael Schmager Adrian Mertens Raheleh Azmi Lukas Klohr Jonas A. Schwenzer Michael Hetterich Uli Lemmer Bryce S. Richards Michael Powalla Ulrich W. Paetzold 《Liver Transplantation》2019,9(12)
High‐quality charge carrier transport materials are of key importance for stable and efficient perovskite‐based photovoltaics. This work reports on electron‐beam‐evaporated nickel oxide (NiOx) layers, resulting in stable power conversion efficiencies (PCEs) of up to 18.5% when integrated into solar cells employing inkjet‐printed perovskite absorbers. By adding oxygen as a process gas and optimizing the layer thickness, transparent and efficient NiOx hole transport layers (HTLs) are fabricated, exhibiting an average absorptance of only 1%. The versatility of the material is demonstrated for different absorber compositions and deposition techniques. As another highlight of this work, all‐evaporated perovskite solar cells employing an inorganic NiOx HTL are presented, achieving stable PCEs of up to 15.4%. Along with good PCEs, devices with electron‐beam‐evaporated NiOx show improved stability under realistic operating conditions with negligible degradation after 40 h of maximum power point tracking at 75 °C. Additionally, a strong improvement in device stability under ultraviolet radiation is found if compared to conventional perovskite solar cell architectures employing other metal oxide charge transport layers (e.g., titanium dioxide). Finally, an all‐evaporated perovskite solar mini‐module with a NiOx HTL is presented, reaching a PCE of 12.4% on an active device area of 2.3 cm2. 相似文献
3.
J. Zhao K. O. Brinkmann T. Hu N. Pourdavoud T. Becker T. Gahlmann R. Heiderhoff A. Polywka P. Görrn Y. Chen B. Cheng T. Riedl 《Liver Transplantation》2017,7(14)
Semitransparent perovskite solar cells (PSCs) are of interest for application in tandem solar cells and building‐integrated photovoltaics. Unfortunately, several perovskites decompose when exposed to moisture or elevated temperatures. Concomitantly, metal electrodes can be degraded by the corrosive decomposition products of the perovskite. This is even the more problematic for semitransparent PSCs, in which the semitransparent top electrode is based on ultrathin metal films. Here, we demonstrate outstandingly robust PSCs with semitransparent top electrodes, where an ultrathin Ag layer is sandwiched between SnOx grown by low‐temperature atomic layer deposition. The SnOx forms an electrically conductive permeation barrier, which protects both the perovskite and the ultrathin silver electrode against the detrimental impact of moisture. At the same time, the SnOx cladding layer underneath the ultra‐thin Ag layer shields the metal against corrosive halide compounds leaking out of the perovskite. Our semitransparent PSCs show an efficiency higher than 11% along with about 70% average transmittance in the near‐infrared region (λ > 800 nm) and an average transmittance of 29% for λ = 400–900 nm. The devices reveal an astonishing stability over more than 4500 hours regardless if they are exposed to ambient atmosphere or to elevated temperatures. 相似文献
4.
Surface Engineering of TiO2 ETL for Highly Efficient and Hysteresis‐Less Planar Perovskite Solar Cell (21.4%) with Enhanced Open‐Circuit Voltage and Stability 下载免费PDF全文
Interfacial studies and band alignment engineering on the electron transport layer (ETL) play a key role for fabrication of high‐performance perovskite solar cells (PSCs). Here, an amorphous layer of SnO2 (a‐SnO2) between the TiO2 ETL and the perovskite absorber is inserted and the charge transport properties of the device are studied. The double‐layer structure of TiO2 compact layer (c‐TiO2) and a‐SnO2 ETL leads to modification of interface energetics, resulting in improved charge collection and decreased carrier recombination in PSCs. The optimized device based on a‐SnO2/c‐TiO2 ETL shows a maximum power conversion efficiency (PCE) of 21.4% as compared to 19.33% for c‐TiO2 based device. Moreover, the modified device demonstrates a maximum open‐circuit voltage (Voc) of 1.223 V with 387 mV loss in potential, which is among the highest reported value for PSCs with negligible hysteresis. The stability results show that the device on c‐TiO2/a‐SnO2 retains about 91% of its initial PCE value after 500 h light illumination, which is higher than pure c‐TiO2 (67%) based devices. Interestingly, using a‐SnO2/c‐TiO2 ETL the PCE loss was only 10% of initial value under continuous UV light illumination after 30 h, which is higher than that of c‐TiO2 based device (28% PCE loss). 相似文献
5.
Effect of Photogenerated Dipoles in the Hole Transport Layer on Photovoltaic Performance of Organic–Inorganic Perovskite Solar Cells 下载免费PDF全文
Judicious choice of transport layer in organic–inorganic halide perovskite solar cells can be one of the essential parameters in photovoltaic design and fabrication techniques. This article reports the effect of optically generated dipoles in transport layer on the photovoltaic actions in active layer in perovskite solar cells with the architecture of indium tin oxide (ITO)/TiO x /CH3NH3PbI3–x Cl x /hole transport layer (HTL)/Au. Here, PTB7‐thieno[3,4‐b]thiophene‐alt‐benzodithiophene and P3HT‐poly(3‐hexylthiophene) are separately used as the HTL with significant and negligible photoinduced dipoles, respectively. Electric field‐induced photoluminescence quenching provides the first‐hand evidence to indicate that the photoinduced dipoles are partially aligned in the amorphous PTB7 layer under the influence of device built‐in field. By monitoring the recombination process through magneto‐photocurrent measurements under device operation condition, it is shown that the photoinduced dipoles in PTB7 layer can decrease the recombination of photogenerated carriers in the active layer in perovskite solar cells. Furthermore, the capacitance measurements suggest that the photoinduced dipoles in PTB7 can decrease charge accumulation at the electrode interface. Therefore, the studies indicate the important role of photoinduced dipoles in the HTL on charge recombination dynamics and provide a fundamental insight on how the polarization in transport layer can influence the device performance in perovskite solar cells. 相似文献
6.
Cesium Doped NiOx as an Efficient Hole Extraction Layer for Inverted Planar Perovskite Solar Cells 下载免费PDF全文
Wei Chen Fang‐Zhou Liu Xi‐Yuan Feng Aleksandra B. Djurišić Wai Kin Chan Zhu‐Bing He 《Liver Transplantation》2017,7(19)
Organic–inorganic hybrid perovskite solar cells have resulted in tremendous interest in developing next generation photovoltaics due to high record efficiency exceeding 22%. For inverted structure perovskite solar cells, the hole extraction layers play a significant role in achieving efficient and stable perovskite solar cell by modifying charge extraction, interfacial recombination losses, and band alignment. Here, cesium doped NiOx is selected as a hole extraction layer to study the impact of Cs dopant on the optoelectronic properties of NiOx and the photovoltaic performance. Cs doped NiOx films are prepared by a simple solution‐based method. Both doped and undoped NiOx films are smooth and highly transparent, while the Cs doped NiOx exhibits better electron conductivity and higher work function. Therefore, Cs doping results in a significant improvement in the performance of NiOx‐based inverted planar perovskite solar cells. The best efficiency of Cs doped NiOx devices is 19.35%, and those devices show high stability as well. The improved efficiency in devices with Cs:NiOx is attributed to a significant improvement in the hole extraction and better band alignment compared to undoped NiOx. This work reveals that Cs doped NiOx is very promising hole extraction material for high and stable inverted perovskite solar cells. 相似文献
7.
In Situ Grain Boundary Functionalization for Stable and Efficient Inorganic CsPbI2Br Perovskite Solar Cells 下载免费PDF全文
Zhaobing Zeng Jing Zhang Xinlei Gan Hongrui Sun Minghui Shang Dagang Hou Chaojie Lu Renjie Chen Yuejin Zhu Liyuan Han 《Liver Transplantation》2018,8(25)
The phase instability and large energy loss are two obstacles to achieve stable and efficient inorganic‐CsPbI3?xBrx perovskite solar cells. In this work, stable cubic perovskite (α)‐phase CsPbI2Br is successfully achieved by Pb(Ac)2 functioning at the grain boundary under low temperature. Ac? strongly coordinates with CsPbI2Br to stabilize the α‐phase and also make the grain size smaller and film uniform by fast nucleation. PbO is formed in situ at the grain boundary by decomposing Pb(Ac)2 at high‐temperature annealing. The semiconducting PbO effectively passivates the surface states, reduces the interface recombination, and promotes the charge transport in CsPbI2Br perovskite solar cells. A 12% efficiency and good stability are obtained for in situ PbO‐passivated CsPbI2Br solar cells, while Pb(Ac)2‐passivated device exhibits 8.7% performance and the highest stability, much better than the control device with 8.5% performance and inferior stability. This article highlights the extrinsic ionic grain boundary functionalization to achieve stable and efficient inorganic CsPbI3?xBrx materials and the devices. 相似文献
8.
Yao Liu Lawrence A. Renna Hilary B. Thompson Zachariah A. Page Todd Emrick Michael D. Barnes Monojit Bag D. Venkataraman Thomas P. Russell 《Liver Transplantation》2017,7(21)
Hybrid organic/inorganic perovskite solar cells are invigorating the photovoltaic community due to their remarkable properties and efficiency. However, many perovskite solar cells show an undesirable current–voltage (I–V) hysteresis in their forward and reverse voltage scans, working to the detriment of device characterization and performance. This hysteresis likely arises from slow ion migration in the bulk perovskite active layer to interfaces which may induce charge trapping. It is shown that interfacial chemistry between the perovskite and charge transport layer plays a critical role in ion transport and I–V hysteresis in perovskite‐based devices. Specifically, phenylene vinylene polymers containing cationic, zwitterionic, or anionic pendent groups are utilized to fabricate charge transport layers with specific interfacial ionic functionalities. The interfacial‐adsorbing boundary induced by the zwitterionic polymer in contact with the perovskite increases the local ion concentration, which is responsible for the observed I–V hysteresis. Moreover, the ion adsorbing properties of this interface are exploited for perovskite‐based memristors. This fundamental study of I–V hysteresis in perovskite‐based devices introduces a new mechanism for inducing memristor behavior by interfacial ion adsorption. 相似文献
9.
High‐Performance Planar Perovskite Solar Cells Using Low Temperature,Solution–Combustion‐Based Nickel Oxide Hole Transporting Layer with Efficiency Exceeding 20% 下载免费PDF全文
Ziye Liu Jingjing Chang Zhenhua Lin Long Zhou Zhou Yang Dazheng Chen Chunfu Zhang Shengzhong Liu Yue Hao 《Liver Transplantation》2018,8(19)
NiOx hole transporting layer has been extensively studied in optoelectronic devices. In this paper, the low temperature, solution–combustion‐based method is employed to prepare the NiOx hole transporting layer. The resulting NiOx thin films show better quality and preferable energy alignment with perovskite thin film compared to high temperature sol–gel‐processed NiOx. With this, high‐performance perovskite solar cells are fabricated successfully with power conversion efficiency exceeding 20% using a modified two‐step prepared MA1?yFAyPbI3?xClx perovskite. This efficiency value is among the highest values for NiOx‐based devices. Various characterizations and analyses provide evidence of better film quality, enhanced charge transport and extraction, and suppressed charge recombination. Meanwhile, the device exhibits much better device stability compared to sol–gel‐processed NiOx and poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate)‐based devices. 相似文献
10.
Targeting Ideal Dual‐Absorber Tandem Water Splitting Using Perovskite Photovoltaics and CuInxGa1‐xSe2 Photocathodes 下载免费PDF全文
Jingshan Luo Zhen Li Shiro Nishiwaki Marcel Schreier Matthew T. Mayer Peter Cendula Yong Hui Lee Kunwu Fu Anyuan Cao Mohammad Khaja Nazeeruddin Yaroslav E. Romanyuk Stephan Buecheler S. David Tilley Lydia Helena Wong Ayodhya N. Tiwari Michael Grätzel 《Liver Transplantation》2015,5(24)
Efficient sunlight‐driven water splitting devices can be achieved by pairing two absorbers of different optimized bandgaps in an optical tandem design. With tunable absorption ranges and cell voltages, organic–inorganic metal halide perovskite solar cells provide new opportunities for tailoring top absorbers for such devices. In this work, semitransparent perovskite solar cells are developed for use as the top cell in tandem with a smaller bandgap photocathode to enable panchromatic harvesting of the solar spectrum. A new CuInxGa1‐xSe2 multilayer photocathode is designed, exhibiting excellent performance for photoelectrochemical water reduction and representing a near‐ideal bottom absorber. When pairing it below a semitransparent CH3NH3PbBr3‐based solar cell, a solar‐to‐hydrogen efficiency exceeding 6% is achieved, the highest value yet reported for a photovoltaic–photoelectrochemical device utilizing a single‐junction solar cell as the bias source under one sun illumination. The analysis shows that the efficiency can reach more than 20% through further optimization of the perovskite top absorber. 相似文献
11.
Crystallinity Preservation and Ion Migration Suppression through Dual Ion Exchange Strategy for Stable Mixed Perovskite Solar Cells 下载免费PDF全文
Tiankai Zhang Mingzhu Long Keyou Yan Minchao Qin Xinhui Lu Xiaoliang Zeng Chi Man Cheng Kam Sing Wong Pengyi Liu Weiguang Xie Jianbin Xu 《Liver Transplantation》2017,7(15)
The mixed perovskite (FAPbI3)1?x (MAPbBr3)x , prepared by directly mixing different perovskite components, suffers from phase competition and a low‐crystallinity character, resulting in instability, despite the high efficiency. In this study, a dual ion exchange (DIE) method is developed by treating as‐prepared FAPbI3 with methylammonium brodide (MABr)/tert‐butanol solution. The converted perovskite thin film shows an optimized absorption edge at 800 nm after reaction time control, and the high crystallinity can be preserved after MABr incorporation. More importantly, it is found that the threshold electrical field to initiate ion migration is greatly increased in DIE perovskite thin film because excess MABr on the surface can effectively heal structural defects located on grain boundaries during the ion exchange process. It contributes to the over‐one‐month moisture stability under ≈65% room humidity (RH) and greatly enhanced light stability for the bare perovskite film. As a result of preserved high crystallinity and simultaneous grain boundary passivation, the perovskite solar cells fabricated by the DIE method demonstrate reliable reproducibility with an average power conversion efficiency (PCE) of 17% and a maximum PCE of 18.1%, with negligible hysteresis. 相似文献
12.
Effect of Electron‐Transport Material on Light‐Induced Degradation of Inverted Planar Junction Perovskite Solar Cells 下载免费PDF全文
Azat F. Akbulatov Lyubov A. Frolova Monroe P. Griffin Ioana R. Gearba Andrei Dolocan David A. Vanden Bout Sergey Tsarev Eugene A. Katz Alexander F. Shestakov Keith J. Stevenson Pavel A. Troshin 《Liver Transplantation》2017,7(19)
This paper presents a systematic study of the influence of electron‐transport materials on the operation stability of the inverted perovskite solar cells under both laboratory indoor and the natural outdoor conditions in the Negev desert. It is shown that all devices incorporating a Phenyl C61 Butyric Acid Methyl ester ([60]PCBM) layer undergo rapid degradation under illumination without exposure to oxygen and moisture. Time‐of‐flight secondary ion mass spectrometry depth profiling reveals that volatile products from the decomposition of methylammonium lead iodide (MAPbI3) films diffuse through the [60]PCBM layer, go all the way toward the top metal electrode, and induce its severe corrosion with the formation of an interfacial AgI layer. On the contrary, alternative electron‐transport material based on the perylendiimide derivative provides good isolation for the MAPbI3 films preventing their decomposition and resulting in significantly improved device operation stability. The obtained results strongly suggest that the current approach to design inverted perovskite solar cells should evolve with respect to the replacement of the commonly used fullerene‐based electron‐transport layers with other types of materials (e.g., functionalized perylene diimides). It is believed that these findings pave a way toward substantial improvements in the stability of the perovskite solar cells, which are essential for successful commercialization of this photovoltaic technology. 相似文献
13.
Hui Wang Fabao Li Pang Wang Rui Sun Wan Ma Mengting Chen Weiqiang Miao Dan Liu Tao Wang 《Liver Transplantation》2020,10(21)
A major limit for planar perovskite solar cells is the trap‐mediated hysteresis and instability, due to the defective metal oxide interface with the perovskite layer. Passivation engineering with fullerenes has been identified as an effective approach to modify this interface. The rational design of fullerene molecules with exceptional electrical properties and versatile chemical moieties for targeted defect passivation is therefore highly demanded. In this work, novel fulleropyrrolidine (NMBF‐X, X?H or Cl) monomers and dimers are synthesized and incorporated between metal oxides (i.e. TiO2, SnO2) and perovskites (i.e. MAPbI3 and (FAPbI3)x(MAPbBr3)1‐x). The fullerene dimers provide superior stability and efficiency improvements compared to the corresponding monomers, with chlorinated fullerene dimers being most effective at coordinating with both metal oxides and perovskite via the chlorine terminals. The non‐encapsulated planar device delivers a maximum power conversion efficiency of 22.3% without any hysteresis, while maintaining over 98% of initial efficiency after ambient storage for 1000 h, and exhibiting an order of magnitude improvement of the T80 lifetime. 相似文献
14.
All‐Oxide MoOx/SnOx Charge Recombination Interconnects for Inverted Organic Tandem Solar Cells 下载免费PDF全文
Tim Becker Sara Trost Andreas Behrendt Ivan Shutsko Andreas Polywka Patrick Görrn Philip Reckers Chittaranjan Das Thomas Mayer Dario Di Carlo Rasi Koen H. Hendriks Martijn M. Wienk René A. J. Janssen Thomas Riedl 《Liver Transplantation》2018,8(10)
Multijunction solar cells are designed to improve the overlap with the solar spectrum and to minimize losses due to thermalization. Aside from the optimum choice of photoactive materials for the respective sub‐cells, a proper interconnect is essential. This study demonstrates a novel all‐oxide interconnect based on the interface of the high‐work‐function (WF) metal oxide MoOx and low‐WF tin oxide (SnOx). In contrast to typical p‐/n‐type tunnel junctions, both the oxides are n‐type semiconductors with a WF of 5.2 and 4.2 eV, respectively. It is demonstrated that the electronic line‐up at the interface of MoOx and SnOx comprises a large intrinsic interface dipole (≈0.8 eV), which is key to afford ideal alignment of the conduction band of MoOx and SnOx, without the requirement of an additional metal or organic dipole layer. The presented MoOx/SnOx interconnect allows for the ideal (loss‐free) addition of the open circuit voltages of the two sub‐cells. 相似文献
15.
Enhanced Light Harvesting in Perovskite Solar Cells by a Bioinspired Nanostructured Back Electrode 下载免费PDF全文
Jian Wei Rui‐Peng Xu Yan‐Qing Li Chi Li Jing‐De Chen Xin‐Dong Zhao Zhong‐Zhi Xie Chun‐Sing Lee Wen‐Jun Zhang Jian‐Xin Tang 《Liver Transplantation》2017,7(20)
Light management holds great promise of realizing high‐performance perovskite solar cells by improving the sunlight absorption with lower recombination current and thus higher power conversion efficiency (PCE). Here, a convenient and scalable light trapping scheme is demonstrated by incorporating bioinspired moth‐eye nanostructures into the metal back electrode via soft imprinting technique to enhance the light harvesting in organic–inorganic lead halide perovskite solar cells. Compared to the flat reference cell with a methylammonium lead halide perovskite (CH3NH3PbI3?x Clx ) absorber, 14.3% of short‐circuit current improvement is achieved for the patterned devices with moth‐eye nanostructures, yielding an increased PCE up to 16.31% without sacrificing the open‐circuit voltage and fill factor. The experimental and theoretical characterizations verify that the cell performance enhancement is mainly ascribed by the broadband polarization‐insensitive light scattering and surface plasmonic effects due to the patterned metal back electrode. It is noteworthy that this light trapping strategy is fully compatible with solution‐processed perovskite solar cells and opens up many opportunities toward the future photovoltaic applications. 相似文献
16.
Low‐Temperature Solution‐Processed CuCrO2 Hole‐Transporting Layer for Efficient and Photostable Perovskite Solar Cells 下载免费PDF全文
Hua Zhang Huan Wang Hongmei Zhu Chu‐Chen Chueh Wei Chen Shihe Yang Alex K.‐Y. Jen 《Liver Transplantation》2018,8(13)
Organic–inorganic hybrid perovskite solar cells (PVSCs) have become the front‐running photovoltaic technology nowadays and are expected to profoundly impact society in the near future. However, their practical applications are currently hampered by the challenges of realizing high performance and long‐term stability simultaneously. Herein, the development of inverted PVSCs is reported based on low temperature solution‐processed CuCrO2 nanocrystals as a hole‐transporting layer (HTL), to replace the extensively studied NiOx counterpart due to its suitable electronic structure and charge carrier transporting properties. A ≈45 nm thick compact CuCrO2 layer is incorporated into an inverted planar configuration of indium tin oxides (ITO)/c‐CuCrO2/perovskite/[6,6]‐phenyl‐C61‐butyric acid methyl ester (PCBM)/bathocuproine (BCP)/Ag, to result in the high steady‐state power conversion efficiency of 19.0% versus 17.1% for the typical low temperature solution‐processed NiOx‐based devices. More importantly, the optimized CuCrO2‐based device exhibits a much enhanced photostability than the reference device due to the greater UV light‐harvesting of the CuCrO2 layer, which can efficiently prevent the perovskite film from intense UV light exposure to avoid associated degradation. The results demonstrate the promising potential of CuCrO2 nanocrystals as an efficient HTL for realizing high‐performance and photostable inverted PVSCs. 相似文献
17.
Self‐Assembly Atomic Stacking Transport Layer of 2D Layered Titania for Perovskite Solar Cells with Extended UV Stability 下载免费PDF全文
Tzu‐Pei Chen Chung‐Wei Lin Shao‐Sian Li Yung‐Han Tsai Cheng‐Yen Wen Wendy Jessica Lin Fei‐Man Hsiao Ya‐Ping Chiu Kazuhito Tsukagoshi Minoru Osada Takayoshi Sasaki Chun‐Wei Chen 《Liver Transplantation》2018,8(2)
A novel atomic stacking transporting layer (ASTL) based on 2D atomic sheets of titania (Ti1?δO2) is demonstrated in organic–inorganic lead halide perovskite solar cells. The atomically thin ASTL of 2D titania, which is fabricated using a solution‐processed self‐assembly atomic layer‐by‐layer deposition technique, exhibits the unique features of high UV transparency and negligible (or very low) oxygen vacancies, making it a promising electron transporting material in the development of stable and high‐performance perovskite solar cells. In particular, the solution‐processable atomically thin ASTL of 2D titania atomic sheets shows superior inhibition of UV degradation of perovskite solar cell devices, compared to the conventional high‐temperature sintered TiO2 counterpart, which usually causes the notorious instability of devices under UV irradiation. The discovery opens up a new dimension to utilize the 2D layered materials with a great variety of homostructrual or heterostructural atomic stacking architectures to be integrated with the fabrication of large‐area photovoltaic or optoelectronic devices based on the solution processes. 相似文献
18.
Andrea Capasso Fabio Matteocci Leyla Najafi Mirko Prato Joka Buha Lucio Cinà Vittorio Pellegrini Aldo Di Carlo Francesco Bonaccorso 《Liver Transplantation》2016,6(16)
Solution‐processed few‐layer MoS2 flakes are exploited as an active buffer layer in hybrid lead–halide perovskite solar cells (PSCs). Glass/FTO/compact‐TiO2/mesoporous‐TiO2/CH3NH3PbI3/MoS2/Spiro‐OMeTAD/Au solar cells are realized with the MoS2 flakes having a twofold function, acting both as a protective layer, by preventing the formation of shunt contacts between the perovskite and the Au electrode, and as a hole transport layer from the perovskite to the Spiro‐OMeTAD. As prepared PSC demonstrates a power conversion efficiency (η) of 13.3%, along with a higher lifetime stability over 550 h with respect to reference PSC without MoS2 (Δη/η = ?7% vs. Δη/η = ?34%). Large‐area PSCs (1.05 cm2 active area) are also fabricated to demonstrate the scalability of this approach, achieving η of 11.5%. Our results pave the way toward the implementation of MoS2 as a material able to boost the shelf life of large‐area perovskite solar cells in view of their commercialization. 相似文献
19.
Mohammad Mahdi Tavakoli Michael Saliba Pankaj Yadav Philippe Holzhey Anders Hagfeldt Shaik Mohammed Zakeeruddin Michael Grtzel 《Liver Transplantation》2019,9(1)
The presence of bulk and surface defects in perovskite light harvesting materials limits the overall efficiency of perovskite solar cells (PSCs). The formation of such defects is suppressed by adding methylammonium chloride (MACl) as a crystallization aid to the precursor solution to realize high‐quality, large‐grain triple A‐cation perovskite films and that are combined with judicious engineering of the perovskite interface with the electron and hole selective contact materials. A planar SnO2/TiO2 double layer oxide is introduced to ascertain fast electron extraction and the surface of the perovskite facing the hole conductor is treated with iodine dissolved in isopropanol to passivate surface trap states resulting in a retardation of radiationless carrier recombination. A maximum solar to electric power conversion efficiency (PCE) of 21.65% and open circuit photovoltage (Voc) of ≈1.24 V with only ≈370 mV loss in potential with respect to the band gap are achieved, by applying these modifications. Additionally, the defect healing enhances the operational stability of the devices that retain 96%, 90%, and 85% of their initial PCE values after 500 h under continuously light illumination at 20, 50, and 65 °C, respectively, demonstrating one of the most stable planar PSCs reported so far. 相似文献
20.
Wei Li Mathias Uller Rothmann Amelia Liu Ziyu Wang Yupeng Zhang Alexander R. Pascoe Jianfeng Lu Liangcong Jiang Yu Chen Fuzhi Huang Yong Peng Qiaoliang Bao Joanne Etheridge Udo Bach Yi‐Bing Cheng 《Liver Transplantation》2017,7(20)
Organic–inorganic hybrid perovskite solar cells with mixed cations and mixed halides have achieved impressive power conversion efficiency of up to 22.1%. Phase segregation due to the mixed compositions has attracted wide concerns, and their nature and origin are still unclear. Some very useful analytical techniques are controversial in microstructural and chemical analyses due to electron beam‐induced damage to the “soft” hybrid perovskite materials. In this study photoluminescence, cathodoluminescence, and transmission electron microscopy are used to study charge carrier recombination and retrieve crystallographic and compositional information for all‐inorganic CsPbIBr2 films on the nanoscale. It is found that under light and electron beam illumination, “iodide‐rich” CsPbI(1+x )Br(2?x ) phases form at grain boundaries as well as segregate as clusters inside the film. Phase segregation generates a high density of mobile ions moving along grain boundaries as ion migration “highways.” Finally, these mobile ions can pile up at the perovskite/TiO2 interface resulting in formation of larger injection barriers, hampering electron extraction and leading to strong current density–voltage hysteresis in the polycrystalline perovskite solar cells. This explains why the planar CsPbIBr2 solar cells exhibit significant hysteresis in efficiency measurements, showing an efficiency of up to 8.02% in the reverse scan and a reduced efficiency of 4.02% in the forward scan, and giving a stabilized efficiency of 6.07%. 相似文献