Piezoelectric properties of substitutionally doped $β$-Ga$_2$O$_3$

Abstract

Modern semiconductor materials are increasingly used in multidisciplinary systems that show cross-interactions between mechanical strains and electronic potentials, which gives rise to ubiquitous applications in high sensitivity, selfpowered sensor devices. One of fundamental prerequisites for such semiconductor materials to exhibit piezoelectric properties is the noncentrosymmetry of the crystal structures. β-Ga2O3 has been an emerging compound semiconductor material due to its ultra-wide bandgap. However the pristine β-Ga2O3 has an inversion center, displaying no piezoelectric effect. This work discovered that doped β-Ga2O3 possesses piezoelectric property, while majority of previous research on doped β-Ga2O3 has been focusing on the increased electrical conductivity. More interestingly, it is unveiled that atomic number of the doping element has a clear relation with the piezoelectric coefficient through first principles analysis.