6-18. Extended shannon radii for perovskites discovery

Runhai Ouyang

Materials Genome Institute, Shanghai University, 99 Shangda Road, Shanghai 200444, China

Abstract: The emerging perovskite solar cell has inspired extensive study of perovskite materials due to their high efficiency and diverse physical properties, with a recent focus on the search of Lead-free alternatives with better stability and environmental benignity. To accelerate materials discovery, descriptors that relate target properties to few key parameters are often used for cheap high-throughput materials screening. Among others, ionic radius is an essential parameter for many important materials properties, with Shannon radii the most widely accepted dataset. Yet, substantial amount of Shannon radii data for unusual oxidation states are missing. In this talk, I will show (1) How the Shannon radii can be consistently extended to unusual oxidation states and arbitrary coordination of cations using a data-driven method; (2) A new criterion for evaluating the formability of three-dimensional single perovskite and over a hundred of predicted new hybrid divalent metal halide perovskites with unusual metal oxidation states; (3) A simple yet predictive descriptor which relates band gap of halide perovskites to the unit cell volume and the constituent ionic radii. These results highlight the critical roles of ionic size to the formability and bandgap of halide perovskites, and the extended Shannon radii to unusual oxidation states will contribute to the exploration of novel compounds.

Key words: Shannon radii; Perovskite; Formability; Band gap; Data-driven

Shannon离子半径扩展及新钙钛矿材料预测

欧阳润海

上海大学材料基因组工程研究院

摘要：近年来，杂化铅基钙钛矿太阳能电池快速提升的能源转化率、低廉的制造成本、以及钙钛矿材料本身丰富的物理性质吸引了对钙钛矿的广泛研究兴趣。目前一个研究焦点是寻找更稳定的环境友好的无铅钙钛矿替代材料。为此，借助准确描述符（联系目标性质与少数关键参数的关系式）进行快速高通量材料筛选是加速新材料发现的一个有效方式。其中，离子半径是描述很多重要性质的关键参数之一，而Shannon离子半径是最为广泛接受的半径数据集。然而，很多元素的重要氧化态缺失相应Shannon半径数据。在此报告中我将介绍：（1）如何通过数据驱动方法将Shannon离子半径自洽地扩展到阳离子非常规氧化态及任何配位环境；（2）评价三维单钙钛矿材料可形成性新标准及一百多个预测的新杂化二价金属卤化物钙钛矿材料；（3）一个简单而有预测能力的卤化物钙钛矿带隙描述符，该描述符只依赖于钙钛矿材料体积及组分离子半径。该工作揭示了离子半径对钙钛矿可形成性及带隙的关键作用，并提供了一套准确的扩展的Shannon离子半径数据集。