Electrical and optical bistability inInxGa1−xAs-GaAs piezoelectric quantum wells

Abstract

Optically induced bistability in the electrical and optical characteristics of a (111)B piezoelectric, strained ${\mathrm{In}}_{0.15}$${\mathrm{Ga}}_{0.85}$As-GaAs single-quantum-well p-i-n structure is reported. We demonstrate that the bistability results from photoinduced electron charge buildup in the quantum well. Charge buildup is enhanced relative to a (100) structure as a consequence of the modified band profile due to the large internal piezoelectric field. A region of hysteresis is observed in the current-voltage characteristics under illumination, with the device being stable in either low- or high-current states. Photoluminescence line-shape analysis and magneto-photoluminescence studies demonstrate that the low- and high-current states correspond to either high or near-zero electron charge (${\mathrm{n}}_{\mathrm{s}}$) in the well, respectively. Simulations of the band profiles using the deduced values of ${\mathrm{n}}_{\mathrm{s}}$ are consistent with the existence of the two different current and charge accumulation states.