A comparative electron paramagnetic resonance study of vanadium in n-type, semi-insulating and p-type CdTe

Abstract

A quantitative electron paramagnetic resonance (EPR) study of vanadium-related defects in semi-insulating and co-doped p-type and n-type bulk CdTe:V shows the VCd donor to be the dominant electrically and optically active defect in semi-insulating photorefractive material. The effective trap density of 4*1015 cm-3 for the VCd0+/ defect, determined by quantitative EPR spectroscopy, is in agreement with the value obtained from photorefractive measurements on the same crystals. A comparison of the total V content with the VCd donor concentration indicates the existence of additional V-related defects not observed in EPR. Surprisingly the neutral donor state, VCd0, is not observed by EPR in the n-type material. No other V-related defects were detected in the n- or p-type material.