The Cd_1-xZn_xTe (x = 0.1) crystals from two different manufacturers were studied by photoconductivity (PC) measurements. The samples 1 and 2 were subjected to chemical etching and irradiation with nanosecond laser pulses. The IR transmittance spectra of the crystals before and after laser irradiation were also monitored. The PC spectrum of the sample 1 had a typical one-band shape while the spectrum of the sample 2 exhibited two bands roughly corresponding to the bandgaps of CdTe and Cd_1-xZn_xTe that could be attributed to inhomogeneities in the surface region of the crystal. The positions of the maximum and red edge of the PC spectra did not correspond to the component compositions x in the bulk of Cd_0.9Zn_0.1Te crystals, however chemical polishing etching of the samples in a brominemethanol solution or/and laser irradiation led to this correspondence. Moreover, depending of laser pulse energy density, irradiation of Cd_1-xZn_xTe crystals resulted in a short-wavelength shift of the PC spectra, transformation of two bands to one in the case of the sample 2, and an increase in the photosensitivity of the semiconductor. The laser processing provided equalization of parameters in the surface and bulk regions.

Date Published: 24 October 2012
PDF: 5 pages
Proc. SPIE 8507, Hard X-Ray, Gamma-Ray, and Neutron Detector Physics XIV, 85071S (24 October 2012); doi: 10.1117/12.937953

Published in SPIE Proceedings Vol. 8507:
Hard X-Ray, Gamma-Ray, and Neutron Detector Physics XIV
Ralph B. James; Arnold Burger; Larry A. Franks; Michael Fiederle, Editor(s)