Abstract

Experimental conditions for a growth of near stoichiometric high resistive CdTe single crystals with a minimized concentration of point defects have to be defined. The position of the stoichiometric line in the pressure-temperature (P-T) phase diagram was evaluated from high-temperature in situ galvanomagntic measurements. Calculations based on a model of two major native defects (Cd vacancy and Cd interstitial) show, that a very small variation of Cd pressure P-Cd results in a strong generation of uncompensated native defects. Modelling of room temperature carrier density in dependence of the deep defect density N-DD, P-Cd, and annealing temperature T shows, that the range of optimal P-Cd, at which the high resistivity can be reached, broadens with increasing N-DD or decreasing T. It is shown, that at low T < 450degreesC the deep defect density < 10(15) cm(-3) is sufficient to grow the high resistive CdTe. CdTe doped with Vanadium is used as a model example.