Abstract
We examined the electrical and optical properties of vanadium-doped GaAs grown by metalorganic vapour phase epitaxy using vanadium tetrachloride (VCl
4) as a novel dopant source. Samples with various vanadium incorporations were investigated. All samples were
n type. The electron concentration dependence on the VCl
4 flow rate was established. At 15
K, by comparison with undoped layers grown in the same conditions, photoluminescence spectra of V-doped exhibited three new emission bands: at 1.41, 1 and 0.72
eV. The 1 and 0.72
eV band emissions were attributed to V
2+ and V
3+ intracenter emission, while the 1.41
eV band was suggested to be a donor-bound transition. The identity of the donor is tentatively attributed to a donor complex that associates vanadium to an arsenic vacancy. From Hall effect as function of temperature, the donor ionisation energy was estimated to be about 102±5
meV.