Investigation on Na Acceptor Level in p -Type Na-Doped ZnMgO Thin Films Prepared by Pulsed Laser Deposition

Na-doped ZnMgO films have been deposited on quartz substrates by pulsed laser deposition and the effect of the oxygen pressure on their electrical properties investigated. The film deposited under optimal conditions exhibited p -type conductivity with representative hole concentration of 1.2 × 10 15 cm −3 , Hall mobility of 8.3 cm 2 V −1 s −1 , and resistivity of 6.7 × 10 2 Ω cm. Temperature-dependent Hall measurements were used to confirm the p -type conductivity and determine the Na-related acceptor level in the ZnMgO films, which was estimated to be 483 ± 21 meV. Temperature-dependent photoluminescence revealed an acceptor level of about 460 meV, close to the result determined by Hall measurements. The Na acceptor is deeper in ZnMgO than in ZnO due to the enlarged bandgap.