Emerging perovskite solar cell technology has inspired extensive study of perovskite materials, with a recent focus on the search of stable and environmentally benign lead-free alternatives. The huge compositional space of the perovskites family necessitates rational strategies, for which predictive descriptors that relate target properties to a few key variables are crucial. Among others, ionic radius plays key roles on many important materials properties. In this work, to unlock the full potential of ionic radius for rational materials design (1) the widely used Shannon radii data set were consistently expanded to more than twice as large by extending to unusual oxidation states and arbitrary coordination, (2) new criterion for improved prediction of perovskites formability was proposed, (3) a general and predictive band gap physical descriptor with radius and normalized volume as inputs was discovered for a wide range of three-dimensional halide perovskites. These results offer new opportunities for perovskites design by exploiting radii.

中文翻译：

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利用离子半径进行卤化物钙钛矿的合理设计

新兴的钙钛矿太阳能电池技术激发了对钙钛矿材料的广泛研究，最近的重点是寻找稳定且对环境无害的无铅替代品。钙钛矿家族的巨大组成空间需要合理的策略，对于这些策略而言，将目标属性与一些关键变量相关联的预测描述符至关重要。其中，离子半径在许多重要的材料特性中起着关键作用。在这项工作中，为了充分发挥离子半径的潜力，进行合理的材料设计（1）通过扩展到不寻常的氧化态和任意配位，将广泛使用的Shannon半径数据集不断扩大到两倍以上，（2）新标准为了更好地预测钙钛矿的可成形性，提出了 （3）发现了一个广泛的，可预测的带隙物理描述符，以半径和归一化体积作为输入，适用于各种三维卤化物钙钛矿。这些结果为利用半径设计钙钛矿提供了新的机会。