Responsivities of n-type GaAs/InGaAs/AlGaAs step multiple-quantum-well infrared detectors

Abstract

The responsivities of bound-to-bound transitions in an n-type Al 0.15Ga0.85As/GaAs/In0.15Ga0.85As multiple-quantum-well infrared photodetector had been measured, using both the 45° facet edge coupling scheme as well as direct back side illumination. It was found that the transverse electric (TE) mode responsivity was slightly redshifted in the 9 μm spectral region, and its magnitude was about 1%, with respect to the mixed TE and transverse magnetic (TM) mode infrared radiation, when direct back side illumination was employed. These observations were in good agreement with theoretical calculations using a 14-band k.p model. The much larger TE response observed when the 45° facet edge coupling scheme was employed was probably due to mesa edge scattering. © 2002 American Institute of Physics.