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. The response is modeled with a numerical device simulator which solves the conventional drift‐diffusion transport equations. Evidence is found for bipolar transport, and the photocurrent response at low internal fields is shown to decay due to the transit time of carriers across the quantum well region. For large internal fields the photocurrent response saturates and the corresponding screening rate is estimated using an analytical device model.