Random electric field induced by interface roughness in GaN/Al x Ga 1-x N multiple-quantum wells

Herein, we present an analytical study of a random electric field induced by interface roughness in GaN/AlxGa1−xN multiple quantum wells (MQWs) grown on c-plane GaN substrate. From the calculation, we reveal that the total root-mean-square of the random electric field induced by the disorder of interfaces is unexpectedly large, i.e. sub-mega-volt per centimeter, even at 0.1 Al compositional ratio in an AlGaN barrier. Through the calculation and analysis, we show that the roughness-induced bulk piezoelectric charge may contribute as an additional strong scattering source in GaN/AlxGa1−xN MQWs.