Recent progress in quantum well infrared photodetectors and imaging arrays

A review of the recent progress in III-V quantum well infrared photodetectors (QWIPs) for focal plane arrays (FPAs) staring infrared imaging system applications is presented in this paper. A discussion of the device physics of the intersubband absorption and hot-carrier transport processes for different types of bound-to-continuum (BTC) and bound-to-miniband (BTM) transition QWIPs is given. The performance parameters such as dark current, spectral responsivity, and detectivity of III-V QWIPs having different structures and materials are discussed. Design of the grating couplers for efficient coupling of normal incidence IR radiation into the quantum wells of n-type QWIPs will be addressed. In addition, a new class of normal incidence p-type strained-layer III-V QWIPs with high BLIP temperature will be depicted. Finally, a discussion of the high sensitivity large area (128x 128) focal plane arrays using GaAs QWIPs for the staring infrared imaging system will also be given.