Abstract

The fabrication of 10-jrni IR detectors from 111—V materials would allow advantageous use of their more highly developed growth and processing technologies compared with II-VI compounds.^1-3 Furthermore, device parameters (e.g., band gap, operating temperature, bandwidth, and speed) can be tailored in ways that are difficult with either II-VI or extrinsic Si detectors. We report here the first demonstration of a novel high-speed IR detector based on intersubband absorption⁴ and sequential resonant tunneling⁵ in doped GaAs/AInGa-i-xAs quantum-well superlattices. We achieved a responsivity of 0.52 A/VV at X = 10.8 (im, art advantageous narrow bandwidth response of AX/X m 10%, and estimated the speed to be «45 ps. From our experiments we determined that the mean free path of the phofogenerated hot electrons through the superlattice is 2500 A.

© 1987 Optical Society of America