Abstract The newly discovered inorganic lead-free double perovskites (A2BB’X6) are comparable to, and suitable replacements to the currently-popular hybrid lead perovskites. These double perovskites demonstrate strong potential for optoelectronic and photo-voltaic applications due to their lead-free low environmental impact, low cost, and reliability. However, this material’s native wide bandgap limits its potential as a solar cell material. In this paper, we theoretically tune the bandgap of various double perovskite materials under high pressure to attempt to improve efficiency, without changing the composition of the materials and thus conserving their environmentally friendly properties. Our results show that after compressing the parameters by nearly 11%, the bandgaps of the materials Cs2AgBiBr6 and Cs2SbAgCl6 dropped from 2.3 eV to approximately 1.55 eV, optimizing their efficiency as perovskites. This work encourages further research into the engineering of bandgaps and novel double perovskite devices for photo-voltaic applications.

中文翻译：

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用于光伏的双钙钛矿 A2(BB') X6 的理论压力调谐带隙

摘要 新发现的无机无铅双钙钛矿（A2BB'X6）可与目前流行的混合铅钙钛矿相媲美，并适合替代。这些双钙钛矿由于其无铅低环境影响、低成本和可靠性，在光电和光伏应用中展现出强大的潜力。然而，这种材料的固有宽带隙限制了其作为太阳能电池材料的潜力。在本文中，我们从理论上调整高压下各种双钙钛矿材料的带隙以试图提高效率，而不改变材料的成分，从而保持其环保性能。我们的结果表明，在将参数压缩近 11% 后，材料 Cs2AgBiBr6 和 Cs2SbAgCl6 的带隙从 2 下降。3 eV 至约 1.55 eV，优化了它们作为钙钛矿的效率。这项工作鼓励进一步研究带隙工程和用于光伏应用的新型双钙钛矿器件。