Non-Thermal Annealing Fabrication of Efficient Planar Perovskite Solar Cells with Inclusion of NH4Cl
Non-Thermal Annealing Fabrication of Efficient Planar Perovskite Solar Cells with Inclusion of NH4Cl
复制标题
非热退火制备含 NH4Cl 的高效平面钙钛矿太阳能电池
DOI：
10.1021/acs.chemmater.5b00041
复制
发表时间：
2015-03-10
影响因子：
8.6
通讯作者：
Liang, Ziqi
中科院分区：
文献类型：
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作者：
Chen, Yani;Zhao, Yixin;Liang, Ziqi
近两年来，有机−无机混杂钙钛矿型太阳能电池引起了人们极大的关注，并成为下一代光伏技术的先行者。1−4钙钛矿型太阳能电池的功率转换效率最近已从2009年的3.8%飙升至20.1%。这些有机−无机杂化钙钛矿化合物采用ABX3型结构，其中A离子为有机阳离子(通常为CH3NH3+、C2H5NH3+、HC-(NH2)2+)，B离子为金属离子(Pb2+、Sn2+、Cu2+)，而X阴离子为卤化物(Cl−、Br2+、I−)。7在典型的钙钛矿结构中，CH3NH3+离子位于立方单元的八角处，而Pb2+离子位于八面体[PbX6]4−团簇的体心。8由于特殊的结构性质，这类有机−无机杂化钙钛矿材料具有许多吸引人的特点，如高吸收系数、可调带隙、良好的双极电荷迁移率、显著低的激子结合能、相当长的电子和空穴扩散长度以及长期的电荷寿命。9−11目前研究最多的有机−无机杂化钙钛矿有三碘钙钛矿CH3NH3PbI3和混合卤化物钙钛矿CH3NH3PbI3−x-Clx和CH3NH3PbI3−xBrx。除了具有成本效益的溶液可加工性优势外，钙钛矿型太阳能电池的效率现在可以与最先进的铜铟镓二硒化物(CIGS)太阳能电池或商业化的硅太阳能电池相媲美，满足了大规模部署太阳能的要求，尽管在商业化之前钙钛矿型太阳能电池存在稳定性和环境问题。目前，钙钛矿型太阳能电池制造中遇到的主要问题之一是对薄膜形貌的精细控制，如表面均匀度和表面覆盖率，这对实现高性能太阳能电池至关重要。13钙钛矿形貌不佳会引起电性分流或陷阱，对电荷的解离和输运产生不利影响，同时极大地增加电荷复合的几率。目前，最常用的钙钛矿层沉积方法包括一步前驱体溶液沉积、两步连续沉积、双源气相沉积和气相辅助溶液法。8、14在这些制备技术中，一步沉积CH3NH3I和PbI2前驱体溶液的等摩尔混合物是最简单的方法。更重要的是，该方法是实现大面积全印刷制造的最有可能的途径之一。然而，它经常涉及形成针状的溶剂化中间体(CH3NH3PbI3·DMF和CH3NH3PbI3·H2O)，这导致对
Organic− inorganic hybrid perovskite based solar cells have attracted considerable research attention and emerged as the forerunner in the next generation photovoltaic technology in the past two years. 1− 4 The power conversion efficiency (PCE) of perovskite solar cells has most recently skyrocketed to a certified 20.1% 5 from 3.8% 6 back in 2009. These organic− inorganic hybrid perovskite compounds adopt ABX3 structure, where the A cations are organic (typically CH3NH3+, C2H5NH3+, HC-(NH2) 2+) and the B cations are metal ions (Pb2+, Sn2+, Cu2+), while the X anions are halides (Cl−, Br−, I−). 7 In a typical perovskite structure, the CH3NH3+ cation resides at the eight corners of the cubic unit, while the Pb2+ cation is located at the body centers of an octahedral [PbX6] 4− cluster. 8 Owing to specific structural properties, such organic− inorganic hybrid perovskites are known to exhibit a plethora of appealing features such as high absorption coefficient, tunable bandgaps, decent ambipolar charge mobility, remarkably low exciton binding energy, substantially long electron and hole diffusion lengths, and long-term charge life. 9− 11 Currently, the most commonly studied organic− inorganic hybrid perovskite are triiodide perovskite CH3NH3PbI3 and mixed halide perovskite CH3NH3PbI3− x-Clx and CH3NH3PbI3− xBrx. Along with advantages of costeffective solution-processability, perovskite solar cells, efficiency is now comparable to state-of-the-art copper indium gallium diselenide (CIGS) solar cells or commercialized silicon solar cells, fulfilling the requirements for the large-scale deployment of solar energy, although there are stability and environmental problems for perovskite solar cells to overcome before commercialization. 12At present, one of the main issues encountered in perovskite solar cell fabrication lies in a fine-control of the film morphology such as surface uniformity and surface coverage, which is of paramount importance to achieve high-performance solar cells. 13 Poor perovskite morphology causes electrical shunt or induces traps, which deleteriously impacts charge dissociation and transport while largely increasing the probability of charge recombination. Currently, the most frequently applied deposition methods for the perovskite layer include one-step precursor solution deposition, two-step sequential deposition, dual-source vapor deposition, and vapor assisted solution process. 8, 14 Among these fabrication techniques, one-step deposition of an equimolar mixture of CH3NH3I and PbI2 precursor solution is the simplest way. More importantly, this method is one of the most possible ways for realizing the large-area full-printing manufacturing. However, it often involves the formation of needle-shaped solvation intermediates (CH3NH3PbI3· DMF and CH3NH3PbI3· H2O), which leads to incomplete coverage of the