Fan Jiandong, Liu Chong, Li Hongliang, Zhang Cuiling, Li Wenzhe, Mai Yaohua
Institute of New Energy Technology, College of Information Science and Technology, Jinan University, Guangzhou, 510632, P. R. China.
Institute of Photovoltaics, College of Physics Science and Technology, Hebei University, Baoding, 071002, P. R. China.
ChemSusChem. 2017 Oct 9;10(19):3839-3845. doi: 10.1002/cssc.201700880. Epub 2017 Aug 4.
The Sn-based perovskite solar cells (PSCs) provide the possibility of swapping the Pb element toward developing toxic-free PSCs. Here, we innovatively employed a molecular self-assembly approach to obtain a series CH NH Pb Sn I (0≤x≤1) perovskite thin films with full coverage. The optimized planar CH NH Pb Sn I PSC with inverted structure was consequently realized with a maximum power conversion efficiency (PCE) over 14 %, which displayed a stabilized power output (SPO) over 12 % within 200 s at 0.6 V forward bias. Afterward, we investigated the factors that limited the efficiency improvement of hybrid Sn-Pb PSCs, and analyzed the possible reason of the hysteresis effect occurred even in the inverted structure cell. Particularly, the oxidation of hybrid Sn-Pb perovskite thin film was demonstrated to be the main reason that limited its further efficiency improvement. The imbalance of charge transport was intensified, which was associated with the increased hole defect-state density and decreased electron defect-state density after Sn was introduced. This study helps tackle the intractable issue regarding the toxic Pb in perovskite devices and is a step forward toward realizing lead-free PSCs with high stability and efficiency.
基于锡的钙钛矿太阳能电池（PSC）为开发无铅毒性的PSC提供了替代铅元素的可能性。在此，我们创新性地采用分子自组装方法，制备了一系列具有全覆盖的CH₃NH₃Pb₁₋ₓSnₓI₃（0≤x≤1）钙钛矿薄膜。最终实现了具有倒置结构的优化平面CH₃NH₃Pb₁₋ₓSnₓI₃PSC，其最大功率转换效率（PCE）超过14%，在0.6 V正向偏压下200秒内显示出超过12%的稳定功率输出（SPO）。随后，我们研究了限制混合Sn-Pb PSC效率提高的因素，并分析了即使在倒置结构电池中也会出现滞后效应的可能原因。特别地，混合Sn-Pb钙钛矿薄膜的氧化被证明是限制其进一步提高效率的主要原因。电荷传输的不平衡加剧，这与引入Sn后空穴缺陷态密度增加和电子缺陷态密度降低有关。这项研究有助于解决钙钛矿器件中棘手的有毒铅问题，是朝着实现具有高稳定性和效率的无铅PSC迈出的一步。
