Modification of Cl doping efficiency in transparent ZnO electrode films by tuning deposition temperature

Abstract

In this study, anion substitution by Cl doping is found to simultaneously enhance carrier concentration by 15% and mobility by 20% in the film deposited at 300 °C. The Cl doping efficiency is remarkably enhanced to 0.88 at% in the film prepared at 300 °C, as compared to room-temperature deposition (0.35 at%). Good O substitution of Cl not only produces free electrons but also reduces oxygen vacancies and trap states, which is confirmed by the Hall measurement and X-ray photoelectron spectroscopy. The sputtered Cl-doped ZnO film obtains the lowest resistivity of 6 × 10−4 Ωcm, and good transparency of 82% in the visible region. It leads to the largest figure of merit for transparent electrodes, which is also better than other previous reports on Cl-doped ZnO films.