A GGA+U study of the optical properties of vanadium doped ZnO with and without single intrinsic vacancy

Using the GGA+U method, we have calculated the optical properties of vanadium (V) doped ZnO with and without single intrinsic (zinc or oxygen) vacancy. Vanadium introduces a new band in the band gap. The new band betters conduction and causes a red shift of the optical properties. Vanadium causes a weak absorption in the infrared region. Zinc vacancy suppresses the infrared absorption and shifts absorption to higher energy. Besides the infrared absorption, oxygen vacancy causes an intense absorption in the visible and near-ultraviolet region. Our study explains the different experiments and extends the use of V-doped ZnO.