Investigation on doping behavior of copper in ZnO thin film

An experiment to determine the electronic and chemical states of Cu in a ZnO crystal was performed using Hall measurement, X-ray photoelectron spectroscopy (XPS) and low-temperature photoluminescence (PL). Cu atoms showed different behaviors in the ZnO matrix as a function of oxygen gas pressure. Metallic copper (Cu-0)-related Cu 2p(3/2) peak was observed in highly n-type ZnO:Cu film deposited in 10mTorr. In the Cu-doped p-type ZnO film prepared in 50mTorr, Cu-Zn(1+)-related peak and small Cu-Zn(2+)-related satellite peak exhibited and the optical acceptor binding energies of Cu3d(9) and Cu3d(10) were 173 and 213 meV, respectively. (C) 2008 Elsevier Ltd. All rights reserved.