Understanding the Potential of 2D Ga2O3 in Flexible Optoelectronic Devices: Impact of Uniaxial Strain and Electric Field

Abstract The discovery of two‐dimensional (2D) Ga 2 O 3 has provided an effective way to further tune the performance of β‐Ga 2 O 3 . Understanding the effects of strain and electric field (E‐field) on 2D Ga 2 O 3 is helpful to explore the mechanism and potential application in the flexible device. Here, transport and optical properties of monolayer Ga 2 O 3 under uniaxial strain and E‐field are investigated. An indirect‐to‐direct band‐gap‐transition occurs under uniaxial tension due to the different variation of π bonding at the valence bands. The band‐gap exhibits a parabolic variation character from compression to tension, and relates to the direction of uniaxial strain. Interestingly, the transport characters are sensitive to the direction of uniaxial strain, and both compression and tension along b direction enhance the mobility of monolayer Ga 2 O 3 , which is inconsistent with that of electron effective mass. The mobility of tensile monolayer Ga 2 O 3 can be enlarged to 48368.14 cm 2 V −1 s −1 , different to that of 2D layered materials. Interestingly, the ultra‐visible absorption coefficients are just enhanced significantly by compression along c direction. Upon monolayer Ga 2 O 3 undergoes large E‐field (>0.5 eV Å −1 ), the band‐gap and anisotropic transport property decreases and even vanishes. The results are useful to reveal the mechanisms and potential of 2D Ga 2 O 3 in the flexible devices.