A metal grating coupled step-bound-to-miniband (SBTM) transition multiquantum well long wavelength infrared photodetector (LWIP) using a lightly strained In_0.07Ga_0.93As quantum well with a short-period Al_0.4Ga_0.6As -GaAs superlattice barrier structure has been developed. The new structure created a potential `step' in the superlattice barrier to block the undesirable electron tunneling current from the heavily doped ground state in the quantum well, which results in a significant reduction in the device dark current. The measured absorbance spectra and photocurrent are in good agreement with our theoretical predictions. The responsivity R_(lambda ) at V_b equals 6 V and T equals 77 K was found equal to 0.2, 0.15 A/W for the backside, and front normal incident illumination, respectively.

Date Published: 1 September 1992
PDF: 9 pages
Proc. SPIE 1685, Infrared Detectors and Focal Plane Arrays II, (1 September 1992); doi: 10.1117/12.137800

Published in SPIE Proceedings Vol. 1685:
Infrared Detectors and Focal Plane Arrays II
Eustace L. Dereniak; Robert E. Sampson, Editor(s)