Investigations on structural, electronic and optical properties of ZnO in two-dimensional configurations by first-principles calculations
| Autor: | Hong-Ji Wang, Jun-Tao Yang, Chang-Ju Xu, Hai-Ming Huang, Qing Min, Yong-Chen Xiong, Shi-Jun Luo |
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| Rok vydání: | 2022 |
| Předmět: | |
| Zdroj: | Journal of Physics: Condensed Matter. 35:014002 |
| ISSN: | 1361-648X 0953-8984 |
| DOI: | 10.1088/1361-648x/ac9d17 |
| Popis: | The electronic structures and optical properties of two-dimensional (2D) ZnO monolayers in a series of configurations were systematically investigated by first-principles calculations with Hubbard U evaluated by the linear response approach. Three types of 2D ZnO monolayers, as planer hexagonal-honeycomb (Plan), double-layer honeycomb (Dlhc), and corrugated tetragonal (Tile) structures, show a mechanical and dynamical stability, while the Dlhc-ZnO is the most energetically stable configuration and Plan-ZnO is the second one. Each 2D ZnO monolayer behaves as a semiconductor with that Plan-, Dlhc-ZnO have a direct band gap of 1.81 eV and 1.85 eV at the Γ point, respectively, while Tile-ZnO has an indirect band gap of 2.03 eV. Interestingly, the 2D ZnO monolayers all show a typical near-free-electron character for the bottom conduction band with a small effective mass, leading to a tremendous optical absorption in the whole visible and ultraviolet window, and this origination was further confirmed by the transition dipole moment. Our investigations suggest a potential candidate in the photoelectric field and provide a theoretical guidance for the exploration of wide-band-gap 2D semiconductors. |
| Databáze: | OpenAIRE |
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