Abstract:
We present control over the ambipolar nature of Te in ZnO and the corresponding optical band gap in epitaxial thin film grown by pulsed laser deposition. Experimentally, the decrease in band gap is found to be strongly dependent on the Te concentration for TeO compared to Te-Zn. Emission at 3 eV for TeZn, irrespective of Te content is explained by first principle calculation considering Zn vacancy in the lattice. An experimental band bowing parameter of similar to 7 eV is obtained for Te-O and is in agreement with modified Becke-Johnson potential (mBJLDA) based theoretical calculation. The physical insight into the nature of band bowing is elucidated. (C) 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
