Wavelength tuning of GaAs/AlGaAs quantum-well infrared photodetectors by thermal interdiffusion

Thermal interdiffusion is used to shift peak response wavelength of quantum well infrared photodetectors. A maximum 0.7 mu m red-shift for 900 degrees C annealed devices compared with as-grown one has been obtained. Error function potential profile is used to calculate the intermixing process. nle large red-shift is attributed to Si-dopant enhanced intermixing. Dark current is decreased about 5 times for 900 degrees C annealed sample than as-grown one,which is attributed to Si-dopant out-diffusion. The experimentally observed reduction in the responsivity is attributed to our-diffusion of Si-dopant and degradation of interfaces.