Response of LWIR HgCdTe Photoconductive Detectors to Ionizing Radiation.
Abstract
The effect of ionizing radiation on 0.09-eV bandgap long wave-length infrared HgCdTe photoconductive detectors at 77 K has been investigated. The results of pulsed gamma, gamma-counting, and gamma-induced noise experiments indicate that the average value of the electron-hole pair creation energy, epsilon rho of Hg 0.8 Cd 0.2 Te is 0.36 plus or minus 0.07 eV. Analysis of gamma-counting and gamma-induced noise experiments indicate that the majority of the gamma events originate from Compton interactions in the surrounding material--for example, glass dewar external to the detector. Initial decay characteristics of the detector response following a prompt gamma pulse appear to depend on the detector material, proceeding either through a bimolecular or a Shockley-Read recombination process. At longer times following the pulse, trap-limited processes become operative in which the fractional level of decay eventually reaches the same value for all the material-preparation techniques evaluated in this work. This applies to detectors in which the surface was left untreated, or was passivated. A detector with the surface treated with a ZnS antireflection coating, however, exhibited an enhanced long time decay response at the largest gamma doses.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1976
- Accession Number
- ADA040397
Entities
People
- Stewart Share
Organizations
- Harry Diamond Laboratories