New photoconductive gain mechanism by electric field modulation in multiquantum-well heterostructures

Abstract
A new type of photoconductivity in semiconductor heterojunctions has been observed. The structures are InP/In0.47Ga0.53As forward‐biased multiquantum‐well pn junctions grown by chemical‐beam epitaxy. This phenomenon manifests itself in a photocurrent proportional to the dark differential conductance. This effect is associated with the partial screening of the electric field in the wells induced, at constant bias, by photogenerated carriers in the wells. The resulting increase of the field in the barriers leads to enhanced injection and photocurrent gain.