Synthesis and Characterization of Optically Transparent and Electrically Conductive Mo-Doped ZnO, F-Doped ZnO, and Mo/F-Codoped ZnO Thin Films via Aerosol-Assisted Chemical Vapor Deposition
Nan Chen, Iqra Ramzan, Shuhui Li, Claire J. Carmalt
Abstract
High Resolution Image Download MS PowerPoint Slide Mo-doped ZnO (MZO), F-doped ZnO (FZO), and Mo/F-codoped ZnO (MFZO) films have been deposited using a simple, cheap, and effective thin-film preparation route, aerosol-assisted chemical vapor deposition (AACVD). ZnO was successfully doped with Mo and/or F, confirmed by X-ray photoelectron spectroscopy (XPS) and by a decrease in unit cell parameters from X-ray diffraction (XRD). XRD also confirmed that all of the films had hexagonal wurtzite ZnO structures. Scanning electron microscopy showed that all of the films had well-defined surface features. The undoped ZnO film had a high resistivity of ∼10 2 Ω·cm, determined by Hall effect measurements, and a visible light transmittance of 72%, determined by ultraviolet–visible (UV–vis)-IR spectroscopy. The transmittance of the doped and codoped films was improved to 75–85%. The ZnO film codoped with 6.2 atom% Mo and 3.6 atom% F, deposited at 550 °C achieved the minimum resistance (5.084 × 10 –3 Ω·cm) with a significant improvement in carrier concentration (5.483 × 10 19 cm –3 ) and mobility (21.78 cm 2 V –1 s –1 ).