Investigation of aluminum-gallium co-doped zinc oxide targets for sputtering thin film and photovoltaic application

Aluminum (Al) and gallium (Ga) co-doped ZnO (AGZ) powder was synthesized by a chemical co-precipitation method and compacted to form targets. In order to demonstrate the effects of Ga additive and analyze the discrepancy between AGZ and Al doped ZnO (AZO), the microstructure, electrical properties and densification of sintered targets were investigated. Further research was carried out on the properties of AGZ thin film and its application on nano-crystalline Si (nc-Si) solar cells. Results showed that Al and Ga co-doped ZnO ceramic targets have higher densities and lower resistivities than Al doped ZnO ceramic targets with the same doping concentration. Similarly, AGZ thin films have lower resistivities than AZO thin films deposited under the same conditions. In addition, Al-Ga co-doping leads to higher carrier concentration and broader optical band gap. The nc-Si solar cell coated with AGZ transparent thin film electrode exhibits higher conversion efficiency. (c) 2013 Elsevier B.V. All rights reserved.