LAUSR

Abstract Sodium-doped ZnCdO films (ZCO:Na) were grown on quartz substrates by radio frequency (RF) reactive magnetron sputtering followed by rapid annealing technique. Hall measurements results underscore the importance of annealing temperature ( T ann ) and annealing time ( t ann ) in obtaining p-type ZCO:Na film. It is found that the recipe to acquiring p-type ZCO:Na film is drive out Na i and H i while preserving Na at the substitutional sites, which can be realized through managing the dissociation of Na-relevant neutral complexes under appropriate T ann and t ann . The optimal p-type ZCO:Na film (sample D) was obtained when the T ann and t ann were set to 600 °C and 30 min, respectively, which possesses a carrier concentration of 2.98 × 10 17  cm −3 , a mobility of 0.225 cm 2 V −1 s −1 and a resistivity of 95.9 Ω cm. XPS results revealed the chemical bonding states of elements in ZCO:Na film. Combining the results of XRD, TEM and XPS, it is demonstrated that the substitution of some Zn sites by Cd and Na atoms (Cd Zn and Na Zn ) takes place in ZCO:Na film. It is observed from absorption spectrum that the band gaps of all ZCO:Na films are smaller than that (3.37 eV) of pure ZnO film. Sample D has a relatively narrow band gap ( E g ) of 3.05 eV, which led to the decrease of the activation energy of Na Zn or other defect acceptor states, exhibiting advantages to realize the p-type conduction conversion in ZCO:Na film. Our results show that the sputtering followed by rapid annealing synthesis route of ZCO:Na film is a promising solution toward obtaining p-type conductivity for future device applications.