(Hg,Cd)Te photoconductive detectors in the 3-5m wavelength range were irradiated with an ultraviolet source of wavelength λ = 0.36611m and power density P0 = 50μW/cm2. The performance such as detectivity (D*λ), responsivity (Rλ), the noise current (iN) and the detector resistance (RD) were measured as a function of irradiation time for a fixed temperature T = 110°K. The measurement indicated that the responsivity changed from Rλ = 0.7 x 103 (A/W) to Rλ = 1.3 x 103 (A/W) for 22 minutes of ultraviolet irradiation. During the same ultraviolet exposure, the noise current increased from iN = 1 x 10-11 (A/Hz1/2) to iN = 1.4 x 10-11 (A/Hz1/2), the detectivity increased from D*λ = 2.7 x 1011 (Cm-Hz1/2/W) to D*λ = 3.8 x 1011 (Cm-Hz1/2/W) and the resistance changed from 680Ω to 950Ω. The corresponding change in the surface potential was calculated and was shown to be from ψs = 0.089 (volt) to ψs = 0.0946 (volt). The ultraviolet irradiation is believed to fill the traps within the insulator with electrons which in turn increases the surface potential. The data indicates that ultraviolet wavelength used for the investigation is only partially effective in filling the insulator traps.

Date Published: 11 June 1981
PDF: 11 pages
Proc. SPIE 0285, Infrared Detector Materials, (11 June 1981); doi: 10.1117/12.965798

Published in SPIE Proceedings Vol. 0285:
Infrared Detector Materials
H. R. Riedl, Editor(s)