Abstrakt
We studied the electrical properties of Cd(0.9)Zn(0.1)Te:In (CZT) single crystals with [In]=3*10(15) at/cm(3) at its high-temperature point-defect equilibrium state under a Cd overpressure. We detailed the influence of thermal treatment and the deviation of stoichiometry on the electron concentration, observing unexpectedly high conductivity and an increase in free-electron density (similar to 1.5-2 orders of magnitude) when annealing the sample at 770 K under a Cd vapor pressure (0.01 atm.).
Prolonged exposure of the samples under these conditions lowered the electron density by two approximately orders-of-magnitude until it approached the intrinsic value. The electron mobility after such treatment increased to CZT maximal values at similar to 460 K (650-700 cm(2)/(V*s)).
Therefore, such annealing can be effective in assuring high-resistive CZT detectors after crystal growth, or by special treatment, thereby eliminating the inclusions. We analyzed these data in the framework of Kroger theory of quasi-chemical reactions, and compared the findings to those obtained for undoped CdTe.