A type-II WSe2/HfSe2 van der Waals heterostructure with adjustable electronic and optical properties
| Autor: | Donghui Wang, Yi Zhang, Yanmin Xu, Weiwei Ju, Guangxiong Hu, Haisheng Li, Enqin Zhao, Tongwei Li |
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| Rok vydání: | 2021 |
| Předmět: |
Materials science
Band gap QC1-999 General Physics and Astronomy vdW heterostructure 02 engineering and technology Electron Semimetal 01 natural sciences First-principles calculations symbols.namesake Optical absorption strength Electric field 0103 physical sciences 010302 applied physics Condensed matter physics business.industry Physics Heterojunction 021001 nanoscience & nanotechnology Semiconductor symbols Direct and indirect band gaps van der Waals force 0210 nano-technology business Band alignment |
| Zdroj: | Results in Physics, Vol 25, Iss, Pp 104250-(2021) |
| ISSN: | 2211-3797 |
| DOI: | 10.1016/j.rinp.2021.104250 |
| Popis: | The construction of van der Waals (vdW) heterostructures is an efficient strategy for attaining more desired specifications. According to first-principles calculations, the WSe2/HfSe2 vdW heterostructure has an indirect band gap from K point to M point with the value of 0.21 eV. A conventional type-II band alignment is constructed for the WSe2/HfSe2 heterostructure, where the electrons and holes are placed in HfSe2 and WSe2 layers, respectively, facilitating the efficient separation of photo-generated electron and hole pairs. Although both WSe2 and HfSe2 monolayers were highly insulating, Kashiwabara group found that WSe2/HfSe2 heterostructure were highly conducting [Adv. Funct. Mater. 2019, 29, 1900354]. Our calculated results suggest that the strain and external electric field can lead to the transition from semiconductor to metal, resulting in high conductivity. The band alignment transition from type-II to type-I can also be obtained by means of in-plane strains and external electric field. The interlayer coupling only affects the values of band gap. Moreover, the investigation on the optical properties shows that the optical absorption intensity of WSe2/HfSe2 heterostructure can attain the order of 105. These findings indicate that the WSe2/HfSe2 vdW heterostructure is promising for efficient optoelectronic nanodevices. |
| Databáze: | OpenAIRE |
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