Methylammonium lead mixed-halide perovskites MAPb(Br_xI_1–x)₃ are promising materials for the preparation of tandem devices. When exposed to light, MAPb(Br_xI_1–x)₃ segregates in iodide- and bromide-rich phases, limiting the achievable photovoltage and hence the attainable device efficiency. To date only solution-processed mixed-halide perovskites have been demonstrated. We present fully vacuum-deposited mixed-halide perovskite thin films with band gap of 1.72 and 1.87 eV, prepared by controlling the deposition rates of the different halide precursors. When used in thin-film devices, these materials lead to power conversion efficiencies of 15.9 and 10.5%, respectively, which are among the highest reported to date for these types of wide band gap absorbers.

中文翻译：

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完全真空处理的宽带隙混合卤化物钙钛矿太阳能电池

甲基铵铅混合卤化物钙钛矿MAPb（Br _x I _{1– x}）₃是制备串联装置的有前途的材料。当暴露于光线下时，MAPb（Br _x I _{1– x}）₃在富碘化物和溴化物的相中分离，限制了可达到的光电压，从而限制了可达到的器件效率。迄今为止，仅证明了溶液处理的混合卤化物钙钛矿。我们介绍了通过控制不同卤化物前体的沉积速率制备的带隙为1.72和1.87 eV的完全真空沉积的混合卤化物钙钛矿薄膜。当用于薄膜器件中时，这些材料分别导致功率转换效率分别为15.9和10.5％，这是迄今为止报道的这类宽带隙吸收器的最高效率。