Co-substitution driven electronic structure modifications in Zn1-xCoxO

We report, the studies on the electronic structure and valence band modifications in sol-gel grown Zn1-xCoxO (x = 0, 0.5 and 0.15) samples, obtained using X-ray photoelectron spectroscopy (XPS) measurements. Structural studies confirm the single phasic hexagonal wurtzite structure having space group P6(3)mc. XPS measurements of Co 2p core level indicate that, Co-ions are in +2 state in ZnO. Using valence band spectroscopy (VBS) and resonant photoemission spectroscopy (RPES) measurements, modifications in the electronic structure of Co-doped ZnO have been understood in the context of increment in the occupation of Co-3d states with Co-content which extends the VB maxima edge. (C) 2014 Elsevier B.V. All rights reserved.