Non-wetting surface-driven high-aspect-ratio crystalline grain growth for efficient hybrid perovskite solar cells.
Non-wetting surface-driven high-aspect-ratio crystalline grain growth for efficient hybrid perovskite solar cells.
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DOI：
10.1038/ncomms8747
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发表时间：
2015-07-20
影响因子：
16.6
通讯作者：
Huang J
中科院分区：
文献类型：
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作者：
Bi C;Wang Q;Shao Y;Yuan Y;Xiao Z;Huang J
在多晶薄膜太阳能电池中需要大纵横比晶粒以减少晶界处的电荷复合;然而，有机铅三卤化物钙钛矿（OTP）膜中的晶粒尺寸通常受到膜厚度的限制。在这里，我们报告了OTP晶粒的生长，具有2.3-7.9的高平均纵横比的非润湿空穴传输层（HTLs），通过抑制异质成核增加核间距，并通过施加较小的阻力促进晶粒生长中的晶界迁移。减小的晶界面积和改善的结晶度将OTP薄膜中的电荷复合显著降低到OTP单晶中的水平。结合几种HTL的高功函数，在1个太阳照射下，在低温处理的平面异质结OTP器件中实现了18.3%的高稳定器件效率。这种增强OTP形态的简单方法为其在其他光电器件中的应用铺平了道路，以增强性能。 混合钙钛矿太阳能电池的性能会因通常发生在晶界处的电荷复合而降低。在这里，作者采用非润湿空穴传输层，其促进具有较少晶界的高度结晶膜的生长，从而提高器件效率。
Large-aspect-ratio grains are needed in polycrystalline thin-film solar cells for reduced charge recombination at grain boundaries; however, the grain size in organolead trihalide perovskite (OTP) films is generally limited by the film thickness. Here we report the growth of OTP grains with high average aspect ratio of 2.3–7.9 on a wide range of non-wetting hole transport layers (HTLs), which increase nucleus spacing by suppressing heterogeneous nucleation and facilitate grain boundary migration in grain growth by imposing less drag force. The reduced grain boundary area and improved crystallinity dramatically reduce the charge recombination in OTP thin films to the level in OTP single crystals. Combining the high work function of several HTLs, a high stabilized device efficiency of 18.3% in low-temperature-processed planar-heterojunction OTP devices under 1 sun illumination is achieved. This simple method in enhancing OTP morphology paves the way for its application in other optoelectronic devices for enhanced performance. The performance of hybrid perovskite solar cells is diminished by charge recombination, which commonly occurs at grain boundaries. Here, the authors employ a non-wetting hole transport layer which promotes the growth of highly crystalline films with fewer grain boundaries, leading to improved device efficiencies.