STRAIN COMPENSATED INGAAS INGAP QUANTUM-WELL INFRARED DETECTOR FOR MIDWAVELENGTH BAND DETECTION/

A high detectivity multiquantum well midinfrared photodetector is repo rted. It is based on a strain compensated InGaAs/InGaP on InP structur e, using bound-to-continuum intersubband absorption, with lambda(P)=4. 9 mu m and similar to 0.5 mu m full width at half maximum. This design is unique by enabling a large critical thickness, thus increasing the quantum efficiency. Photodetectors with background-limited performanc e (BLIP) with detectivity of D-lambda(BLIP) = 3.2X10(10) cm root<(Hz) over bar>/W up to 110 K, with only ten quantum well periods were imple mented. Arguments are given to predict an optimized background-limited performance for this design up to 135 K. (C) 1998 American Institute of Physics. [S0003-6951(98)03132-5].