ZnO transparent conducting films deposited by pulsed laser deposition for solar cell applications

Abstract

Low resistivity and highly transparent ZnO conducting films for thin film solar cell applications were fabricated at low temperature by pulsed laser deposition. Al-, B- and Ga-doped ZnO films were deposited on Corning 7059 glass substrate at a substrate temperature of 200 °C. The Al-doped ZnO films were found to have the lowest resistivity of 2.5×10 −4 Ω cm and an average optical transmission of 91% for wavelengths between 400 and 1100 nm. The values of the Ga-doped film were 2.5×10 −4 Ω cm and 81%, respectively. Owing to the higher optical transmission in the near infrared region, the photovoltaic cell performance of a Cu(In,Ga)Se 2 thin film solar cell with an Al-doped ZnO window outperformed a cell fabricated with a Ga-doped ZnO window.