Investigation of detection wavelength of Quantum Well Infrared-Photodetector

We report on GaAs/AlGaAs quantum well infrared photodetectors (QWIPs) that can cover the spectral range of 3.6-25 ㎛. One advantage of the GaAs QWIPs is the wavelength tenability as a function of their structural parameters. We have performed a systematic calculation on the detection wavelength of a typical GaAs/Al x Ga 1-x As multi-quantum-well photodetector, with the aluminum mole fraction (x) of Al x Ga 1-x As barrier in the range of 0.15- 0.43 and the quantum-well width range from 30 to 60 A. Design and fabrication of a QWIP based on GaAs/Al 0.23 Ga 0.77 As structure with 37 A-thick well width has been carried out. The calculated operation wavelength of the QWIP is in a good agreement with the experimental data taken by photo response and activation energy calculation from thermal quenching of integrated photoluminescence.