Tuning of detection wavelength of GaAs/AlGaAs quantum-well IR photo-detectors by thermal interdiffusion

Abstract

Thermal interdiffusion is used to shift peak response wavelength of the quantum well infrared photodetectors (QWIP). A maximum of 0.7 /spl mu/m red-shift for 900/spl deg/C annealed devices compared with as-grown one has been obtained. Error function potential profile is used to calculate the intermixing process. The large red shift is attributed to Si-dopant enhanced intermixing. Both the dark current and responsivity of QWIP are decreased for 900/spl deg/C annealed sample than as-grown one, which is attributed to decrease of electron concentration in the quantum well due to Si-dopant outdiffusion.