Wu Hsuan-Ta, Cheng Yu-Ting, Leu Ching-Chich, Wu Shih-Hsiung, Shih Chuan-Feng
Department of Electrical Engineering, National Cheng Kung University, Tainan 70101, Taiwan.
Department of Chemical and Materials Engineering, National University of Kaohsiung, Kaohsiung 81148, Taiwan.
Nanomaterials (Basel). 2019 Apr 27;9(5):666. doi: 10.3390/nano9050666.
Incorporating additives into organic halide perovskite solar cells is the typical approach to improve power conversion efficiency. In this paper, a methyl-ammonium lead iodide (CHNHPbI, MAPbI) organic perovskite film was fabricated using a two-step sequential process on top of the poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) hole-transporting layer. Experimentally, water and potassium halides (KCl, KBr, and KI) were incorporated into the PbI precursor solution. With only 2 vol% water, the cell efficiency was effectively improved. Without water, the addition of all of the three potassium halides unanimously degraded the performance of the solar cells, although the crystallinity was improved. Co-doping with KI and water showed a pronounced improvement in crystallinity and the elimination of carrier traps, yielding a power conversion efficiency (PCE) of 13.9%, which was approximately 60% higher than the pristine reference cell. The effect of metal halide and water co-doping in the PbI layer on the performance of organic perovskite solar cells was studied. Raman and Fourier transform infrared spectroscopies indicated that a PbI-dimethylformamide-water related adduct was formed upon co-doping. Photoluminescence enhancement was observed due to the co-doping of KI and water, indicating the defect density was reduced. Finally, the co-doping process was recommended for developing high-performance organic halide perovskite solar cells.
在有机卤化物钙钛矿太阳能电池中添加添加剂是提高功率转换效率的典型方法。本文采用两步连续工艺在聚（3,4-乙撑二氧噻吩）聚苯乙烯磺酸盐（PEDOT:PSS）空穴传输层上制备了甲基铵碘化铅（CH₃NH₃PbI₃，MAPbI₃）有机钙钛矿薄膜。实验中，将水和卤化钾（KCl、KBr和KI）加入到PbI₂前驱体溶液中。仅加入2 vol%的水就能有效提高电池效率。在不加水的情况下，尽管结晶度有所提高，但添加所有三种卤化钾均一致降低了太阳能电池的性能。KI和水共掺杂显示出结晶度的显著提高以及载流子陷阱的消除，功率转换效率（PCE）达到13.9%，比原始参考电池高出约60%。研究了PbI₂层中金属卤化物和水共掺杂对有机钙钛矿太阳能电池性能的影响。拉曼光谱和傅里叶变换红外光谱表明，共掺杂时形成了与PbI₂-二甲基甲酰胺-水相关的加合物。由于KI和水共掺杂观察到光致发光增强，表明缺陷密度降低。最后，推荐采用共掺杂工艺来开发高性能有机卤化物钙钛矿太阳能电池。
