Department of Chemistry, University of Nebraska-Lincoln , Lincoln, Nebraska 68588, United States.
J Am Chem Soc. 2017 Jun 14;139(23):8038-8043. doi: 10.1021/jacs.7b04219. Epub 2017 Jun 6.
The power-conversion efficiency (PCE) of lead halide perovskite photovoltaics has reached 22.1% with significantly improved structural stability, thanks to a mixed cation and anion strategy. However, the mixing element strategy has not been widely seen in the design of lead-free perovskites for photovoltaic application. Herein, we report a comprehensive study of a series of lead-free and mixed tin and germanium halide perovskite materials. Most importantly, we predict that RbSnGeI possesses not only a direct bandgap within the optimal range of 0.9-1.6 eV but also a desirable optical absorption spectrum that is comparable to those of the state-of-the-art methylammonium lead iodide perovskites, favorable effective masses for high carrier mobility, as well as a greater resistance to water penetration than the prototypical inorganic-organic lead-containing halide perovskite. If confirmed in the laboratory, this new lead-free inorganic perovskite may offer great promise as an alternative, highly efficient solar absorber material for photovoltaic application.
得益于混合阳离子和阴离子策略，卤铅钙钛矿光伏的能量转换效率（PCE）已达到 22.1%，同时结构稳定性也得到了显著提高。然而，在用于光伏应用的无铅钙钛矿的设计中，混合元素策略并未得到广泛应用。在此，我们报告了一系列无铅和混合锡和锗卤化物钙钛矿材料的综合研究。最重要的是，我们预测 RbSnGeI 不仅具有在 0.9-1.6eV 之间的直接带隙，而且具有与最先进的甲脒碘化铅钙钛矿相当的理想光吸收光谱，有利于实现高载流子迁移率的有效质量，以及比原型含铅卤化物钙钛矿更高的抗水渗透能力。如果在实验室中得到证实，这种新的无铅无机钙钛矿可能有望成为一种替代的、高效的太阳能吸收材料，用于光伏应用。
