Sb-doped ZnO (SZO) films were deposited on c-plane sapphire substrates by dual ion beam sputtering deposition system and subsequently annealed in-situ in vacuum and in various proportions of O2/(O2 + N 2)% from 0% (N2) to 100% (O2). Hall measurements established all SZO films were p-type, as was also confirmed by typical diode-like rectifying current-voltage characteristics from p-ZnO/n-ZnO homojunction. SZO films annealed in O2 ambient exhibited higher hole concentration as compared with films annealed in vacuum or N2 ambient. X-ray photoelectron spectroscopic analysis confirmed that Sb 5+ states were more preferable in comparison to Sb3+ states for acceptor-like SbZn-2VZn complex formation in SZO films.
Bibliographical noteFunding Information:
This work was partially supported by Department of Science and Technology (DST) Fast Track Scheme for Young Scientist No. SR/FTP/ETA-101/2010, DST Science and Engineering Research Board (SERB) Project No. SR/S3/EECE/0142/2011, and Council of Scientific and Industrial Research (CSIR) Project No. 22(0608)/12/EMR-II. We are also grateful to the AFM Facility equipped at Sophisticated Instrument Centre at IIT Indore.