PERFORMANCE ASSESSMENT OF QUANTUM-WELL INFRARED PHOTODETECTORS

The performance of GaAs/AlGaAs quantum well infrared photodetectors sp ecified in terms of background limited temperature T-b and specific de tectivity D has been calculated based on realistic detector parameter s. It is found that for a detector with an external quantum efficiency eta of 6.9%, T-b is 76 K for a cutoff wavelength of 10 mu m. This val ue of T-b agrees with the recent experimental result and is significan tly higher than the previous estimation given by M. A. Kinch and A. Ya riv [Appl. Phys. Lett. 55, 2093 (1989)]. if eta is unity, the projecte d T-b can be as high as 88 K with a D of 2.2X10(11) cm root Hz/W. For a lower temperature operation, D increases to 7.5X10(11) cm root Hz/ W at 77 K, comparable to that of a HgCdTe detector.