EXTENDED LONG-WAVELENGTH LAMBDA=11-15-MU-M GAAS/ALXGA1-XAS QUANTUM-WELL INFRARED PHOTODETECTORS

Success has been achieved in extending the spectral wavelength of GaAs/AlxGa1-xAs quantum-well infrared photodetectors to significantly longer wavelengths, lambda = 11-15-mu-m. High responsivity R(p) = 0.5 A/W, high quantum efficiency eta = 12%, and high detectivity D* = 3 x 10(10) cm square-root Hz/W, as well as an excellent noise equivalent temperature difference NE-DELTA-T = 4 mK have been achieved at T = 50 K. High performance NE-DELTA-T = 19 mK has also been achieved at an even higher temperature of T = 60 K.