Efficient and stable CH 3 NH 3 PbI 3-x (SCN) x planar perovskite solar cells fabricated in ambient air with low-temperature process
Efficient and stable CH 3 NH 3 PbI 3-x (SCN) x planar perovskite solar cells fabricated in ambient air with low-temperature process
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DOI：
10.1016/j.jpowsour.2017.11.070
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发表时间：
2018-02
影响因子：
9.2
通讯作者：
Zongbao Zhang;Yang Zhou;Yangyang Cai;Hui Liu;Qiqi Qin;Xubing Lu;Xingsen Gao;L. Shui;Sujuan Wu-Suju
中科院分区：
文献类型：
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作者：
Zongbao Zhang;Yang Zhou;Yangyang Cai;Hui Liu;Qiqi Qin;Xubing Lu;Xingsen Gao;L. Shui;Sujuan Wu-Suju
采用两步法制备了以CH 3 NH3 PbI 3-x（SCN）x（SCN：硫氰酸盐）为活性层、低温处理的TiO 2薄膜为基片的平板钙钛矿太阳能电池。在Pb（SCN）2前驱体中加入碱金属硫氰酸盐（NaSCN、KSCN），以改善CH 3 NH3 PbI 3-x（SCN）x钙钛矿层的微观结构，提高所制备的PSC的性能。在最佳添加浓度下，NaSCN和KSCN改性的PSC的光催化效率分别为16.59%和15.63%，远高于未添加添加剂的PSC的光催化效率12.73%。这种改善主要归因于增强的电子输运、降低的复合速率以及具有大晶粒尺寸和低晶界缺陷密度的显著改善的微观结构。重要的是，揭示了在碱金属硫氰酸盐添加剂的最佳浓度下的改性PSC表现出比参考PSC显著改善的对潮湿环境的稳定性，并且连续暴露于潮湿空气而不包封超过45天仅记录了约5%的效率降低。这些发现提供了一种通过在环境空气中的低加工温度来制造高效且稳定的PSC的简易方法，这两者对于PSC的未来实际应用都是高度优选的。
Planar perovskite solar cells (PSCs) based on CH3NH3PbI3-x(SCN)x(SCN: thiocyanate) active layer and low-temperature processed TiO2films are fabricated by a sequential two-step method in ambient air. Here, alkali thiocyanates (NaSCN, KSCN) are added into Pb(SCN)2precursor to improve the microstructure of CH3NH3PbI3-x(SCN)xperovskite layers and performance of the as-prepared PSCs. At the optimum concentrations of alkali thiocyanates as additives, the as-prepared NaSCN-modified and KSCN-modified PSCs demonstrate the efficiencies of 16.59% and 15.63% respectively, being much higher than 12.73% of the reference PSCs without additives. This improvement is primarily ascribed to the enhanced electron transport, reduced recombination rates and much improved microstructures with large grain size and low defect density at grain boundaries. Importantly, it is revealed that the modified PSCs at the optimized concentrations of alkali thiocyanates additives exhibit remarkably improved stability than the reference PSCs against humid circumstance, and a continuous exposure to humid air without encapsulation over 45 days only records about 5% degradation of the efficiency. These findings provide a facile approach to fabricate efficient and stable PSCs by low processing temperature in ambient air, both of which are highly preferred for future practical applications of PSCs.