Uncooled indium antimonide (InSb) photoconductors were studied to determine their primary noise source, spectral response, and maximum attainable spectral detectivity. The dominant noise component was determined by theoretically analyzing the background photon generation- recombination noise, thermal generation-recombination noise, and Johnson noise, using conditions of the experimental setup. It was shown that at room temperature (300 K) Johnson noise was predominant. Using this fact, an expression was derived for spectral detectivity which gave a value of 1.3 X 10⁸ cm-Hz^1/2/watt for a 25.2 k(Omega) photoconductor and 5.9 X 10⁸ cm-Hz^1/2/watt for a 10 k(Omega) photoconductor. The measurements from the experiment showed a peak wavelength response at 5 micrometer and a cutoff wavelength (50% of maximum) at 5.5 micrometer. The average peak spectral detectivity for the 25.2 k(Omega) photoconductor was 1.17 X 10⁸ cm- Hz^1/2/watt and for the 10 k(Omega) photoconductor, 4.48 X 10⁸ cm- Hz^1/2/watt. These results compared well with theory.

Date Published: 8 September 1995
PDF: 10 pages
Proc. SPIE 2552, Infrared Technology XXI, (8 September 1995); doi: 10.1117/12.218257

Published in SPIE Proceedings Vol. 2552:
Infrared Technology XXI
Bjorn F. Andresen; Marija Strojnik, Editor(s)