Infrared absorption of an In0.2Ga0.8As/GaAs quantum-well infrared photodetector employing a p-n-p camel diode structure

Far-infrared absorption of an In0.2Ga0.8As/GaAs multiple-quantum-well infra red photodetector employing a p-n-p camel diode structure is studied. The d etector showed a photocurrent response to normal incident light at approxim ately 3 mum due to the intersubband hole transition, which is attributed to the strong hole-band mixing of the strained multiple quantum well. Applica tion of the camel diode structure to the photodetector substantially reduce d the dark hole current, resulting in an improved detectivity. (C) 2001 Ame rican Institute of Physics.