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Improving the Performance and Stability of Inverted Planar Flexible Perovskite Solar Cells Employing a Novel NDI‐Based Polymer as the Electron Transport Layer 下载免费PDF全文
Hong Il Kim Myeong‐Jong Kim Kyoungwon Choi Chaesung Lim Yun‐Hi Kim Soon‐Ki Kwon Taiho Park 《Liver Transplantation》2018,8(16)
A new naphthalene diimide (NDI)‐based polymer with strong electron withdrawing dicyanothiophene (P(NDI2DT‐TTCN)) is developed as the electron transport layer (ETL) in place of the fullerene‐based ETL in inverted perovskite solar cells (Pero‐SCs). A combination of characterization techniques, including atomic force microscopy, scanning electron microscopy, grazing‐incidence wide‐angle X‐ray scattering, near‐edge X‐ray absorption fine‐structure spectroscopy, space‐charge‐limited current, electrochemical impedance spectroscopy, photoluminescence (PL), and time‐resolved PL decay, is used to demonstrate the interface phenomena between perovskite and P(NDI2DT‐TTCN) or [6,6]‐phenyl‐C61‐butyric acid methyl ester (PCBM). It is found that P(NDI2DT‐TTCN) not only improves the electron extraction ability but also prevents ambient condition interference by forming a hydrophobic ETL surface. In addition, P(NDI2DT‐TTCN) has excellent mechanical stability compared to PCBM in flexible Pero‐SCs. With these improved functionalities, the performance of devices based on P(NDI2DT‐TTCN) significantly outperform those based on PCBM from 14.3 to 17.0%, which is the highest photovoltaic performance with negligible hysteresis in the field of polymeric ETLs. 相似文献
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The work functions for charge transport layers in perovskite solar cells affect device performance significantly. In this work, the regular poly(3,4‐ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) is modified by adding a polymer electrolyte PSS‐Na to improve its HTL function in perovskite solar cells. The modified PEDOT:PSS films (called m‐PEDOT:PSS) possess higher work function than the regular one. Its energy level matches the valence band of perovskite very well, leading to enhanced Voc and PCE (power conversion efficiency). When CH3NH3PbI3 is used as the light absorber, the cell with PEDOT:PSS HTL gives a Voc of 0.96 V and a PCE of 12.35%, while the cell with m‐PEDOT:PSS layer gives a Voc of 1.11 V and a PCE of 15.56%. Enhanced Voc and PCE are also achieved when CH3NH3PbI2Br or CH3NH3PbBr3 is used as the light absorber. The m‐PEDOT:PSS/CH3NH3PbBr3/PC61BM solar cells demonstrate an outstanding Voc of 1.52 V. 相似文献
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Stable Inverted Planar Perovskite Solar Cells with Low‐Temperature‐Processed Hole‐Transport Bilayer 下载免费PDF全文
Zhongmin Zhou Xing Li Molang Cai Fengxian Xie Yongzhen Wu Zhang Lan Xudong Yang Yinghuai Qiang Ashraful Islam Liyuan Han 《Liver Transplantation》2017,7(22)
Low‐temperature‐processed perovskite solar cells (PSCs), which can be fabricated on rigid or flexible substrates, are attracting increasing attention because they have a wide range of potential applications. In this study, the stability of reduced graphene oxide and the ability of a poly(triarylamine) underlayer to improve the quality of overlying perovskite films to construct hole‐transport bilayer by means of a low‐temperature method are taken advantage of. The bilayer is used in both flexible and rigid inverted planar PSCs with the following configuration: substrate/indium tin oxide/reduced graphene oxide/polytriarylamine/CH3NH3PbI3/PCBM/bathocuproine/Ag (PCBM = [6,6]‐phenyl‐C61‐butyric acid methyl ester). The flexible and rigid PSCs show power conversion efficiencies of 15.7 and 17.2%, respectively, for the aperture area of 1.02 cm2. Moreover, the PSC based the bilayer shows outstanding light‐soaking stability, retaining ≈90% of its original efficiency after continuous illumination for 500 h at 100 mW cm?2. 相似文献
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Polymer Doping for High‐Efficiency Perovskite Solar Cells with Improved Moisture Stability 下载免费PDF全文
Jiexuan Jiang Qian Wang Zhiwen Jin Xisheng Zhang Jie Lei Haijun Bin Zhi‐Guo Zhang Yongfang Li Shengzhong Liu 《Liver Transplantation》2018,8(3)
Each component layer in a perovskite solar cell plays an important role in the cell performance. Here, a few types of polymers including representative p‐type and n‐type semiconductors, and a classical insulator, are chosen to dope into a perovskite film. The long‐chain polymer helps to form a network among the perovskite crystalline grains, as witnessed by the improved film morphology and device stability. The dewetting process is greatly suppressed by the cross‐linking effect of the polymer chains, thereby resulting in uniform perovskite films with large grain sizes. Moreover, it is found that the polymer‐doped perovskite shows a reduced trap‐state density, likely due to the polymer effectively passivating the perovskite grain surface. Meanwhile the doped polymer formed a bridge between grains for efficient charge transport. Using this approach, the solar cell efficiency is improved from 17.43% to as high as 19.19%, with a much improved stability. As it is not required for the polymer to have a strict energy level matching with the perovskite, in principle, one may use a variety of polymers for this type of device design. 相似文献
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Organic‐inorganic halide perovskite materials have become a shining star in the photovoltaic field due to their unique properties, such as high absorption coefficient, optimal bandgap, and high defect tolerance, which also lead to the breathtaking increase in power conversion efficiency from 3.8% to over 22% in just seven years. Although the highest efficiency was obtained from the TiO2 mesoporous structure, there are increasing studies focusing on the planar structure device due to its processibility for large‐scale production. In particular, the planar p‐i‐n structure has attracted increasing attention on account of its tremendous advantages in, among other things, eliminating hysteresis alongside a competitive certified efficiency of over 20%. Crucial for the device performance enhancement has been the interface engineering for the past few years, especially for such planar p‐i‐n devices. The interface engineering aims to optimize device properties, such as charge transfer, defect passivation, band alignment, etc. Herein, recent progress on the interface engineering of planar p‐i‐n structure devices is reviewed. This review is mainly focused on the interface design between each layer in p‐i‐n structure devices, as well as grain boundaries, which are the interfaces between polycrystalline perovskite domains. Promising research directions are also suggested for further improvements. 相似文献
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Wenzhan Xu Luyao Zheng Xiaotao Zhang Yu Cao Tianyu Meng Dezhen Wu Lei Liu Wenping Hu Xiong Gong 《Liver Transplantation》2018,8(14)
In the past years, hybrid perovskite materials have attracted great attention due to their superior optoelectronic properties. In this study, the authors report the utilization of cobalt (Co2+) to partially substitute lead (Pb2+) for developing novel hybrid perovskite materials, CH3NH3Pb1‐xCoxI3 (where x is nominal ratio, x = 0, 0.1, 0.2 and 0.4). It is found that the novel perovskite thin films possess a cubic crystal structure with superior thin film morphology and larger grain size, which is significantly different from pristine thin film, which possesses the tetragonal crystal structure, with smaller grain size. Moreover, it is found that the 3d orbital of Co2+ ensures higher electron mobilities and electrical conductivities of the CH3NH3Pb1‐xCoxI3 thin films than those of pristine CH3NH3Pb4 thin film. As a result, a power conversion efficiency of 21.43% is observed from perovskite solar cells fabricated by the CH3NH3Pb0.9Co0.1I3 thin film. Thus, the utilization of Co, partially substituting for Pb to tune physical properties of hybrid perovskite materials provides a facile way to boost device performance of perovskite solar cells. 相似文献
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Analysis of Ion‐Diffusion‐Induced Interface Degradation in Inverted Perovskite Solar Cells via Restoration of the Ag Electrode 下载免费PDF全文
Straightforward evidence for ion‐diffusion‐induced interfacial degradation in inverted perovskite solar cells is presented. Over 1000 h, solar cells inevitably undergo degradation, especially with respect to the current density and fill factor. The Ag electrode is peeled off and re‐evaporated to investigate the effect of the Ag/[6,6]‐phenyl C71 butyric acid methyl ester (PCBM) interfacial degradation on the photovoltaic performance at days 10 (240 h), 20 (480 h), 30 (720 h), and 40 (960 h). The power conversion efficiency increases after the Ag electrode restoration process. While the current density shows a slightly decreased value, the fill factor and open‐circuit voltage increase for the new electrode devices. The decrease in the activation energy due to the restored Ag electrode induces recovery of the fill factor. The diffused I? ions react with the PCBM molecules, resulting in a quasi n‐doping effect of PCBM. Upon electrode exchange, the reversible interaction between the iodine ions and PCBM causes current density variation. The disorder model for the open‐circuit voltage over a wide range of temperatures explains the open‐circuit voltage increase at every electrode exchange. Finally, the degradation mechanism of the inverted perovskite solar cell over 1000 h is described under the proposed recombination system. 相似文献
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Amino‐Functionalized Conjugated Polymer as an Efficient Electron Transport Layer for High‐Performance Planar‐Heterojunction Perovskite Solar Cells 下载免费PDF全文
Chen Sun Zhihong Wu Hin‐Lap Yip Hua Zhang Xiao‐Fang Jiang Qifan Xue Zhicheng Hu Zhanhao Hu Yan Shen Mingkui Wang Fei Huang Yong Cao 《Liver Transplantation》2016,6(5)
An amino‐functionalized copolymer with a conjugated backbone composed of fluorene, naphthalene diimide, and thiophene spacers (PFN‐2TNDI) is introduced as an alternative electron transport layer (ETL) to replace the commonly used [6,6]‐Phenyl‐C61‐butyric acid methyl ester (PCBM) in the p–i–n planar‐heterojunction organometal trihalide perovskite solar cells. A combination of characterizations including photoluminescence (PL), time‐resolved PL decay, Kelvin probe measurement, and impedance spectroscopy is used to study the interfacial effects induced by the new ETL. It is found that the amines on the polymer side chains not only can passivate the surface traps of perovskite to improve the electron extraction properties, they also can reduce the work function of the metal cathode by forming desired interfacial dipoles. With these dual functionalities, the resulted solar cells outperform those based on PCBM with power conversion efficiency (PCE) increased from 12.9% to 16.7% based on PFN‐2TNDI. In addition to the performance enhancement, it is also found that a wide range of thicknesses of the new ETL can be applied to produce high PCE devices owing to the good electron transport property of the polymer, which offers a better processing window for potential fabrication of perovskite solar cells using large‐area coating method. 相似文献
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Solar Cells: Amino‐Functionalized Conjugated Polymer as an Efficient Electron Transport Layer for High‐Performance Planar‐Heterojunction Perovskite Solar Cells (Adv. Energy Mater. 5/2016) 下载免费PDF全文
Chen Sun Zhihong Wu Hin‐Lap Yip Hua Zhang Xiao‐Fang Jiang Qifan Xue Zhicheng Hu Zhanhao Hu Yan Shen Mingkui Wang Fei Huang Yong Cao 《Liver Transplantation》2016,6(5)
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Inverted,Environmentally Stable Perovskite Solar Cell with a Novel Low‐Cost and Water‐Free PEDOT Hole‐Extraction Layer 下载免费PDF全文
Yi Hou Hong Zhang Wei Chen Shi Chen Cesar Omar Ramirez Quiroz Hamed Azimi Andres Osvet Gebhard J. Matt Eitan Zeira Jan Seuring Nina Kausch‐Busies Wilfried Lövenich Christoph J. Brabec 《Liver Transplantation》2015,5(15)
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Somnath Mahato Arup Ghorai Sanjeev Kumar Srivastava Mantu Modak Sudarshan Singh Samit K. Ray 《Liver Transplantation》2020,10(30)
The synthesis of single‐crystalline β‐CsPbI3 perovskite nanorods (NRs) using a colloidal process is reported, exhibiting their improved photostability under 45–55% humidity. The crystal structure of CsPbI3 NRs films is investigated using Rietveld refined X‐ray diffraction (XRD) patterns to determine crystallographic parameters and the phase transformation from orthorhombic (γ‐CsPbI3) to tetragonal (β‐CsPbI3) on annealing at 150 °C. Atomic resolution transmission electron microscopy images are utilized to determine the probable atomic distribution of Cs, Pb, and I atoms in a single β‐phase CsPbI3 NR, in agreement with the XRD structure and selected area electron diffraction pattern, indicating the growth of single crystalline β‐CsPbI3 NR. The calculation of the electronic band structure of tetragonal β‐CsPbI3 using density functional theory (DFT) reveals a direct transition with a lower band gap and a higher absorption coefficient in the solar spectrum, as compared to its γ‐phase. An air‐stable (45–55% humidity) inverted perovskite solar cell, employing β‐CsPbI3 NRs without any encapsulation, yields an efficiency of 7.3% with 78% enhancement over the γ‐phase, showing its potential for future low cost photovoltaic devices. 相似文献
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