ZnO Thin Film Deposition for TCO Application in Solar Cell

Abstract

ZnO is a well-known suitable candidate for the Transparent Conducting Oxide (TCO) layer of thin film compound solar cells. In this paper we have discussed the deposition of ZnO thin film on glass substrate by reactive DC magnetron sputtering using oxygen as a reactive gas. Samples are prepared by varying oxygen flow rates during the deposition process. After deposition, samples are annealed at 300°C for 2 hours in vacuum environment. All the properties of the film are measured before and after annealing. All the samples are tested for the optical transparency, band gap, and electrical resistivity before and after annealing. Band gap of film is observed to be 3.2 eV. XRD and SEM measurements of the samples show the variation in the crystal structure and surface morphology of the film with varying oxygen flow rate and annealing also. Around 600 nm thick ZnO film with 1.5×10-3 Ω·cm resistivity and 80% transparency without any doping is achieved.