High carrier mobilities and broad absorption spectra in twisted and non-twisted bilayer GaN, BN, and ZnO structures

Abstract

Stacking is effective in modulating the properties of two-dimensional (2D) materials, and more interesting properties exist in twisted stacking systems. The electronic and optical properties of twisted-13.17°, twisted-21.78°, and non-twisted-AA’ structures of GaN, BN, and ZnO have been studied by using first-principles. The calculated results indicate that all structures are stable, and the band gaps of the three structures are modulated effectively. Compared with the monolayer, the twisted structures of GaN, BN, and ZnO can enhance absorption peaks and broaden the absorption spectra. The carrier mobilities of the twisted and non-twisted structures have been investigated by using DP theory. The twisted-13.17° and twisted-21.78° structures of the BN exhibit much high hole mobilities along the y direction of 55.92 and 44.30 @103 cm2 V−1 s−1 respectively. The twisted-13.17° structure of ZnO exhibits much high electron mobilities of 56.81 (x direction) and 16.57 (y direction) @103 cm2 V−1 s−1. The band gap, carrier mobility, and absorption spectrum of the twisted and non-twisted GaN, BN, and ZnO stacking structures have been modulated effectively, and these stacking structures will promise important application prospects in the field of ultraviolet broadband electronic devices and photoelectric devices.