Resonant-cavity-enhanced p-type GaAs/AlGaAs quantum-well infrared photodetectors

Resonant cavities are used to enhance the absorption efficiency in p-type GaAs/AlGaAs quantum-well infrared photodetectors. The cavities are fabricated by applying thick gold films on the detector bottom sides after substrate removal via selective wet etching. The observed peak enhancement and spectral shape are in good agreement with model predictions. Peak absorption of about 25% is obtained for the device studied.