The most prominent mechanism of dark current in infrared detectors based on intersubband transitions in quantum wells (QWIP) is due to interaction of electrons with longitudinal optical phonons. Theoretical expressions are derived for the carrier lifetime, and for generation currents due to both photo-excitation as well as thermal excitation in a quantum well. Detector gain is discussed briefly. Calculated values of thermal generation currents and the ratio of photo-current to thermal current are found to accord well with experimental data. Finally the BLIP performance of QWIPs is investigated and the theory gives T_BLIP equals 81 K for a 9 micrometers cut-off detector with a 2D grating and optical cavity, for 300 K background temperature, optics f-number equals 1 with 100% transmission, and if a photo- to dark current ratio equals 1 criterion is used.

Date Published: 24 April 1995
PDF: 11 pages
Proc. SPIE 2397, Optoelectronic Integrated Circuit Materials, Physics, and Devices, (24 April 1995); doi: 10.1117/12.206927

Published in SPIE Proceedings Vol. 2397:
Optoelectronic Integrated Circuit Materials, Physics, and Devices
Manijeh Razeghi; Yoon-Soo Park; Gerald L. Witt, Editor(s)