Abstract
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.
Original language | English (US) |
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Pages (from-to) | 1085-1091 |
Number of pages | 7 |
Journal | Materials Horizons |
Volume | 4 |
Issue number | 6 |
DOIs | |
State | Published - Nov 2017 |
ASJC Scopus subject areas
- General Materials Science
- Mechanics of Materials
- Process Chemistry and Technology
- Electrical and Electronic Engineering