Effects of different annealing temperatures on the physical, optical, and electrical characteristics and chemical bonds of Ga and F Co-doped ZnO films

Abstract

In this study, we would investigate the effect of annealing temperature on the physical, optical, and electrical characteristics and chemical bonds of F- and Ga-co-doped ZnO (FGZO) Films. At first, 3 wt% Ga2O3 was mixed with 97 wt% ZnO to form the Ga-doped ZnO ceramic target, and the radio frequency (RF) magnetron sputtering method was used to deposit FGZO films. 0.2% CF4 flow rate (CF4/Ar) was controlled using the mixing gas of CF4 and pure Ar, and the mixing gas was introduced during the deposition process, which acted as the source of F− ions. FGZO films were deposited on the EagleXG glass and the films’ thickness was about 300 nm by controlling the deposition time. After FGZO films were deposited, they were annealed at 200, 300, and 400 °C. A comparative study of composition of FGZO films was investigated using secondary-ion mass spectrometry (SIMS) to analyze the distributions of F, Zn, Ga, and C elements, respectively, as the annealing temperature was changed. Another comparative study of FGZO films was that we proposed a modified Burstein-Moss (BM) equation to investigate the relationship between the carrier concentration and the shift of optical energy bandgap. Third comparative study of surfaces of FGZO films were investigated using X-ray photoelectron spectroscopy (XPS) to find the variations of the chemical bonds.

Keywords

• Ga and F co-dope
• CF4
• X-ray photoelectron spectroscope
• Burstein-Moss (BM) equation
• Chemical bond