Facile synthesis of highly oriented p-type aluminum co-doped zinc oxide film with aqua ammonia

Zinc oxide (ZnO) is a wide band-gap material with excellent optoelectronic properties. However, the application of ZnO to optoelectronic devices using ZnO has been hindered by the difficulty in obtaining a stable p-type doping. The paper demonstrates that, with a proper selection of the nitrogen precursor, a solution processable, highly c-axis oriented, stable, and p-type aluminium co-doped ZnO (NZO) formation can be obtained. In this study, the NZO films were characterized by using EDS, Raman spectroscopy, photoluminescence, and electrical measurements, respectively. The films were then synthesized through a sol–gel process that was below 600 °C. For the comparative study, NZO films without the Al co-doping were also prepared by sputter. It is observed and shown that, with the formation of nitrous oxide, the basic deposition condition will be more beneficial towards the formation of p-type ZnO.

Research highlights▶ Highly c-axis oriented crystalline nitrogen/aluminium co doped zinc oxide film can be obtained through selection of chemicals. ▶ p-Type and solution processable zinc oxide film can be achieved by combination of earth abundant Zn, Al and N containing chemicals. ▶ Ammonia hydroxide was found to be excellent source towards formation of high quality p-type zinc oxide.