By combining high-throughput experiments and first-principles calculations based on the DFT-ACBN0 approach, we have investigated the energy band gap of Sr-, Pb-, and Bi-substituted BaSnO₃ over wide concentration ranges. We show that the band gap energy can be tuned from 3 to 4 eV by chemical substitution. Our work indicates the importance of considering the mixed-valence nature and clustering effects upon substitution of BaSnO₃ with Pb and Bi. Starting from the band gap of ∼3.4 eV for pure BaSnO₃, we find that Pb substitution changes the gap in a nonmonotonic fashion, reducing it by as much as 0.3 eV. Bi substitution provides a monotonic reduction but introduces electronic states into the energy gap due to Bi clustering. Our findings provide new insight into the ubiquitous phenomena of chemical substitutions in perovskite semiconductors with mixed-valence cations that underpin their physical properties.

中文翻译：

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BaSnO ₃通过化学取代的系统能带隙调谐：簇在混合价钙钛矿中的作用

通过结合基于DFT-ACBN0方法的高通量实验和第一性原理计算，我们研究了宽浓度范围内Sr-，Pb-和Bi取代的BaSnO ₃的能带隙。我们表明，可以通过化学取代将带隙能量从3 eV调整为4 eV。我们的工作表明，考虑BaSnO ₃被Pb和Bi取代时的混合价性质和聚集效应的重要性。从纯BaSnO _3的约3.4 eV的带隙开始，我们发现Pb取代以非单调的方式改变了间隙，将间隙减小了0.3 eV。Bi取代提供了单调减少，但由于Bi聚类而将电子态引入了能隙。我们的发现为钙钛矿半导体中普遍存在的具有化学价基础的混合价阳离子的化学取代现象提供了新的见解。