Both Sb₂S₃ and Sb₂Se₃ have been studied as promising photocatalytic and photovoltaic semiconductors because of their suitable bandgaps, high light absorption coefficients and good stability. Through forming the mixed-anion Sb₂(S,Se)₃ alloys, the bandgaps and lattice parameters can be tuned and a band structure engineering design of semiconductor heterostructures becomes possible. However, the properties of the disordered Sb₂(S,Se)₃ alloys are currently not clear. Using first-principles calculations, we show that the alloys are highly miscible with low formation enthalpies, so composition-variable and uniform alloys can be fabricated under room temperature. The bandgaps of the alloys change almost linearly as the alloy composition (S/Se ratio) varies, indicating that the bandgap engineering can be quite flexible. The calculations of the defect properties show that there are dozens of detrimental defects producing deep levels in the bandgap of the alloy under the Sb-rich (Se-poor) condition, which can cause serious electron–hole non-radiative recombination and limit the minority carrier lifetime. The formation of these detrimental defects can be largely suppressed under the Sb-poor condition, so we propose that the Sb-poor (Se-rich) condition should be adopted for fabricating Sb₂(S,Se)₃ alloys as photocatalytic and photovoltaic light-absorber semiconductors with long minority carrier lifetimes.

中文翻译：

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准一维Sb2（S，Se）3合金作为带隙可调和耐缺陷的光催化半导体。

由于Sb ₂ S ₃和Sb ₂ Se ₃具有合适的带隙，高的光吸收系数和良好的稳定性，它们都已被研究为有前途的光催化和光伏半导体。通过形成混合阴离子Sb ₂（S，Se）₃合金，可以调整带隙和晶格参数，并且可以进行半导体异质结构的能带结构工程设计。但是，无序Sb ₂（S，Se）_3的性质目前尚不清楚合金。使用第一性原理计算，我们显示出该合金可高度混溶且形成焓低，因此可以在室温下制备成分可变且均匀的合金。合金的带隙随合金成分（S / Se比）的变化而几乎呈线性变化，这表明带隙工程可以非常灵活。缺陷性质的计算表明，在富Sb（Se-poor）条件下，合金的带隙中会产生数十个有害缺陷，这些缺陷会产生深能级，这会引起严重的电子-空穴非辐射复合并限制了少数缺陷载流子寿命。这些不良缺陷的形成可以在贫Sb条件下得到很大程度的抑制，₂（S，Se）₃合金作为具有短载流子寿命长的光催化和光伏吸光半导体。