Abstract Recently, two-dimensional (2D) semiconducting materials with appropriate direct band gaps have attracted considerable attention, due to their great potential application in photoelectric devices. In this study, by using first-principles calculations we propose new PbFCl-type ternary structures of single layers (SLs) and double layers (DLs), namely KAB (A = Cu, Au and B = S, Se). The results indicate that SLs and DLs of KAB are direct band gap semiconductors, ranging from 0.5 eV to 1.4 eV. More importantly, electron mobilities of KCuS, KAuS and KCuSe are larger than 104 cm2 V−1 s−1, and the superiority of optical absorption during visible light region reveals a potential application prospect in photoelectric devices. These findings provide alternative candidates for the application in photoelectric materials and are conductive to understanding the intrinsic properties and potentials of new-type 2D materials.

中文翻译：

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新型二维 KAB（A = Cu、Au、B = S、Se）光电材料具有突出的载流子迁移率和光学特性

摘要 近年来，具有适当直接带隙的二维 (2D) 半导体材料由于其在光电器件中的巨大潜在应用而引起了广泛关注。在这项研究中，通过使用第一性原理计算，我们提出了单层 (SL) 和双层 (DL) 的新 PbFCl 型三元结构，即 KAB（A = Cu、Au 和 B = S、Se）。结果表明，KAB 的 SL 和 DL 是直接带隙半导体，范围从 0.5 eV 到 1.4 eV。更重要的是，KCuS、KAuS 和 KCuSe 的电子迁移率大于 104 cm2 V-1 s-1，可见光区光吸收的优越性揭示了在光电器件中的潜在应用前景。