Lone pair driven anisotropy in antimony chalcogenide semiconductors.
Lone pair driven anisotropy in antimony chalcogenide semiconductors.
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DOI：
10.1039/d1cp05373f
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发表时间：
2021-09
期刊：
影响因子：
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通讯作者：
Xinwei Wang;Zhenzhu Li;Seán R. Kavanagh;A. Ganose;A. Walsh
中科院分区：
文献类型：
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作者：
Xinwei Wang;Zhenzhu Li;Seán R. Kavanagh;A. Ganose;A. Walsh
硫化锑（Sb2S3）和硒化物（Sb2Se3）已经成为薄膜光伏化合物中有前途的地球丰富的替代品。这些材料的一个显著特征是它们的各向异性晶体结构，其由准一维（1D）[Sb4X6]n带组成。据报道，带之间的相互作用本质上是货车范德华（vdW），因此在文献中通常将Sb 2 X 3分类为1D半导体。然而，基于第一性原理计算，在这里，我们表明，带间相互作用存在于Sb2X3超越VDW制度。根据电子结构分析，各向异性结构的起源与Sb 5s孤对电子的立体化学活性有关。进一步研究了结构各向异性对太阳能电池相关的电子、介电和光学性质的影响，包括存在用于载流子传输的高维费米表面。我们的研究提供了指导方针，优化性能的Sb2X3为基础的photoprophics通过设备结构的基础上，潜在的晶体各向异性。
Antimony sulfide (Sb2S3) and selenide (Sb2Se3) have emerged as promising earth-abundant alternatives among thin-film photovoltaic compounds. A distinguishing feature of these materials is their anisotropic crystal structures, which are composed of quasi-one-dimensional (1D) [Sb4X6]n ribbons. The interaction between ribbons has been reported to be van der Waals (vdW) in nature and Sb2X3 are thus commonly classified in the literature as 1D semiconductors. However, based on first-principles calculations, here we show that inter-ribbon interactions are present in Sb2X3 beyond the vdW regime. The origin of the anisotropic structures is related to the stereochemical activity of the Sb 5s lone pair according to electronic structure analysis. The impacts of structural anisotropy on the electronic, dielectric and optical properties relevant to solar cells are further examined, including the presence of higher dimensional Fermi surfaces for charge carrier transport. Our study provides guidelines for optimising the performance of Sb2X3-based photovoltaics via device structuring based on the underlying crystal anisotropy.