| Autor: |
Yi JX; University of Chinese Academy of Sciences and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China., Zhang RZ; University of Chinese Academy of Sciences and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China., Zhang YY; University of Chinese Academy of Sciences and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China., Du SX; University of Chinese Academy of Sciences and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China.; Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, People's Republic of China. |
| Abstrakt: |
Copper selenide (Cu 2 Se) has attracted significant attention due to the extensive applications in thermoelectric and optoelectronic devices over the last few decades. Among various phase structures of Cu 2 Se, layered Cu 2 Se exhibits unique properties, such as purely thermal phase transition, high carrier mobility, high optical absorbance and high photoconductivity. Herein, we carry out a systematic investigation for the electronic structures of layered Cu 2 Se with several exchange-correlation functionals at different levels through first-principle calculations. It can be found that the electronic structures of layered Cu 2 Se are highly sensitive to the choice of functionals, and the correction of on-site Coulomb interaction also has a noticeable influence. Comparing with the results calculated with hybrid functional and G 0 W 0 method, it is found that the electronic structures calculated with LDA + U functional are relatively accurate for layered Cu 2 Se. In addition, the in-plane biaxial strain can lead to the transition of electronic properties from metal to semiconductor in the layered Cu 2 Se, attributed to the change of atomic orbital hybridization. Furthermore, we explore the spin-orbit coupling (SOC) effect of Cu 2 Se and find that the weak SOC effect on electronic structures mainly results from spatial inversion symmetry of Cu 2 Se. These findings provide valuable insights for further investigation on this compound.
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