GEXSI1-X INFRARED DETECTORS .2. CARRIER ESCAPE PROBABILITY AND DETECTOR PERFORMANCE

GexSi1-x/Si heterojunction internal photoemission (HIP) detectors with thresholds in the medium-wave infrared and long-wave infrared (LWIR) regions were fabricated and characterized. Measurements of the photore sponse are fit well by a theory which takes into account the scatterin g of excited carriers. The probability of escape of an excited hole is calculated and compared with that observed in another detector, the m ultiple quantum well structure. It is shown that HIP detectors can ach ieve background-limited performance in the LWIR region when operated a t 40 K. (C) 1997 American Institute of Physics.