Gold–sulfur interfaces, including self-assembled monolayers of thiol molecules on gold surfaces, thiolate-protected gold nanoclusters, and gold sulfide complexes, have attracted intensive interest due to their promising applications in electrochemistry, bioengineering, and nanocatalysis. Herein, we predict two hitherto unreported two-dimensional (2D) Au₆S₂ monolayer polymorphs, named as G-Au₆S₂ and T-Au₆S₂. The global-minimum G-Au₆S₂ monolayer can be viewed as a series of [–S–Au–]_n and [–Au₄–]_n chains packed together in parallel. The metastable T-Au₆S₂ monolayer resembles the widely studied T-MoS₂ monolayer structure with each Mo atom substituted with an octahedral Au₆ cluster, while the S atom is bonded with three Au atoms in a μ₃ bridging mode. The G-Au₆S₂ monolayer is predicted to be metallic. The T-Au₆S₂ monolayer is predicted to be a semiconductor with a direct bandgap of 1.48 eV and high carrier mobility of 2721 cm² V⁻¹ s⁻¹, ∼10 times higher than that of semiconducting H-MoS₂. Moreover, the T-Au₆S₂ monolayer can absorb sunlight efficiently over almost the entire solar spectrum. These properties render the G- and T-Au₆S₂ monolayers promising materials for advanced applications in microelectronics and optoelectronics.

中文翻译：

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Au ₆ S ₂单层片：金属和半导体多晶型物

金硫界面，包括金表面硫醇分子的自组装单分子层，硫醇盐保护的金纳米簇和硫化金络合物，由于它们在电化学，生物工程和纳米催化中的应用前景广阔而引起了广泛的关注。在本文中，我们预测了两个迄今未报告的二维（2D）Au ₆ S ₂单层多晶型，分别称为G-Au ₆ S ₂和T-Au ₆ S ₂。全局最小G-Au ₆ S ₂单层可以视为一系列[–S–Au–] _n和[–Au ₄ –] _n链条平行排列在一起。亚稳T-的Au ₆小号₂单层类似于广泛研究T-的MoS ₂与每个沫原子与八面体的Au取代的单层结构₆簇，而S原子与在μ3个Au原子键合的₃桥接模式。预计G-Au ₆ S ₂单层是金属的。预计T-Au ₆ S ₂单层是具有1.48 eV的直接带隙和2721 cm ² V ^-1 s ^-1的高载流子迁移率的半导体，比半导体H-MoS ₂高约10倍。而且，T-Au ₆ S ₂单层可以在几乎整个太阳光谱上有效地吸收日光。这些特性使得G-和T-Au ₆ S ₂单层有望成为微电子和光电子领域先进应用的材料。