Au6S2 monolayer sheets: metallic and semiconducting polymorphs
Au6S2 monolayer sheets: metallic and semiconducting polymorphs
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Au6S2 单层片：金属和半导体多晶型物
DOI：
10.1039/c7mh00461c
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发表时间：
2017
影响因子：
13.3
通讯作者：
Zeng Xiao Cheng
中科院分区：
文献类型：
--
作者：
Wu Qisheng;Xu Wen Wu;Qu Bingyan;Ma Liang;Niu Xianghong;Wang Jinlan;Zeng Xiao Cheng
金-硫界面，包括巯基分子在金表面的自组装单层膜、巯基保护的金纳米团簇和金硫化物配合物，由于其在电化学、生物工程和纳米催化中的应用前景而引起了人们的广泛兴趣。在此，我们预测两个迄今未报道的二维（2D）Au 6S 2单层多晶型物，命名为G-Au 6S 2和T-Au 6S 2。G-Au_6S_2单分子层是由[-S-Au_4-]_n和[-S-Au_4-]_n两种链并联而成。亚稳态的T-Au_6S_2单分子膜类似于广泛研究的T-Mo_S_2单分子膜结构，每个Mo原子被八面体Au_6原子团簇取代，而S原子以μ3桥接模式与3个Au原子键合。G-Au 6S 2单层被预测为金属。T-Au 6S 2单层被预测为具有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10倍。此外，T-Au 6S 2单层可以在几乎整个太阳光谱上有效地吸收太阳光。这些特性使得G-和T-Au 6S 2单层材料在微电子学和光电子学中的高级应用具有前景。
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.