Noise characteristics of GaAs-AlGaAs heterojunction punch-through phototransistors

Novel GaAs-AlGaAs heterojunction phototransistors with a delta -doped base have been fabricated. Very high gain and low output noise have been measure d, The measured noise is composed of shot noise associated with collector q uiescent bias current and amplified shot noise due to collector leak curren t for nonpassivated devices. The high gain and low intrinsic noise characte ristics of these transistors make them very promising in weak light detecti on.