Effect of Annealing on Microstructures and Properties of N-Doped Al: ZnO Thin Films

The N-doped Al: ZnO (AZO) thin films were deposited by RF magnetron sputtering on glass substrate. The influence of the annealing temperature on the microstructures and properties of the N-doped AZO was investigated with X-ray diffraction, ultraviolet infrared spectroscopy, X-ray photoelectron spectroscopy and Hall Effect measurement. The results show that the annealing temperature had a major positive impact. To be specific, annealing at 400℃ for 15 min significantly improved the microstructures, electrical and optical properties of the N-doped AZO coatings. The improved properties include a hole carrier concentration of 3. 738 × 10²⁰ cm^-3, a resistivity of 1. 299 ×10^-2Ω·cm and an optical transmittance of over 85% in the visible light region. The fact that the density of Noacceptor defects is higher than that of the (N2) odonor defects possibly explains the transformation from n-type into ptype of the N-doped AZO coatings.