ELECTRIC-FIELD SCREENING IN A MULTIPLE-QUANTUM-WELL OPTICALLY ADDRESSED SPATIAL LIGHT-MODULATOR

The transmission and photocurrent of a multiple-quantum-well optically addressed spatial light modulator are measured to study the screening dynamics of the internal electric field under uniform illumination. T he response is modeled with a numerical device simulator which solves the conventional drift-diffusion transport equations. Evidence is foun d for bipolar transport, and the photocurrent response at low internal fields is shown to decay due to the transit time of carriers across t he quantum well region. For large internal fields the photocurrent res ponse saturates and the corresponding screening rate is estimated usin g an analytical device model. (C) 1996 American Institute of Physics.