Editors : A. Burger, M. Fiederle, L. Franks, K. Lynn, D.L. Perry, K. Yasuda
a1 Department of Electrical Engineering, University of South Carolina, Columbia, SC 29208, USA
Cd0.9Zn0.1Te (CZT) detector grade crystals were grown from zone refined Cd, Zn, and Te (7N) precursor materials, using the tellurium solvent method. These crystals were grown using a high temperature vertical furnace designed and installed in our laboratory. The furnace is capable of growing up to 8” diameter crystals, and custom pulling and ampoule rotation functions using custom electronics were furnished for this setup. CZT crystals were grown using excess Te as a solvent with growth temperatures lower than the melting temperatures of CZT (1092°C). Tellurium inclusions were characterized through IR transmittance maps for the grown CZT ingots. The crystals from the grown ingots were processed and characterized using I-V measurements for electrical resistivity, thermally stimulated current (TSC), and electron beam induced current (EBIC). Pulse height spectra (PHS) measurements were carried out using a 241Am (59.6 keV) radiation source, and an energy resolution of ~4.2% FWHM was obtained. Our investigation demonstrates high quality detector grade CZT crystals growth using this low temperature solvent method.