SHORT-WAVELENGTH (1-4 MU-M) INFRARED DETECTORS USING INTERSUBBAND TRANSITIONS IN GAAS-BASED QUANTUM-WELLS

We explore the possibility of covering the short wavelength infrared r egion using intersubband transitions in GaAs-based quantum wells. We i nvestigate InGaAs wells with AlAs thin confining barriers. For this ty pe of double-barrier resonant-final-state detectors, the dark current decreases with increasing detection wavelength. Photocurrents due to i ntersubband transition are observed down to a wavelength of about 1 mu m. The spectra also reveal interesting physical effects apparently re lated to the indirect band minima at the X point. The responsivity for the 3-4 mu m detectors reaches up to 0.01 A/W; and the background lim ited temperature is in the range of 80-100 K. [S0021-8979(98)08011-6]