Growth of Chromium-Doped GaAs Single Crystals by the Gradient Freeze Method

Chromium-doped GaAs single crystals are grown by a new technique in which the growth rate is initially high and lowered automatically by a preprogramed furnace cooling rate in the conventional gradient freeze method. It is shown that Si and Cr distribution in Cr-doped GaAs single crystals along the growth direction depends on crystal growth rate. The effect of growth rate on resistivity and leakage current distribution of Cr-doped GaAs single crystals is also reported. Distribution of deep levels in the crystal grown by the new technique and the relation to impurity distribution are investigated by photoluminescence spectroscopy. 20 ref.--AA