High Sensitivity Low Dark Current 10microns GaAs Quantum Well Infrared Photodetectors.

By increasing the quantum well barrier width, we have dramatically reduced the tunneling dark current by an order of magnitude and thereby significantly increased the black body detectivity D sub BB sup *. For a GaAs quantum well infrared detector having a cutoff wavelength of lambda sub c = 10.7microns we have achieved D sub BB sup * = 1.0 x 10 sup sup (10) cm sqrt Hz /W at T = 68 K, a temperature which is readily achievable with a cryogenic cooler.