Electrical and optical properties of Al-doped zinc-oxide thin films deposited at room temperature by using the continuous composition spread method

Al-doped ZnO (AZO) thin films were deposited on glass substrates at room temperature by using the continuous composition spread (CCS) method. CCS is a thin-film growth method for various Al_xZn_1-xO thin film compositions with a binary or ternary composition spread, and the critical properties can be evaluated as functions of position, which is directly related to material composition, by using an automated probe station. Various compositions of Al-doped ZnO thin films deposited at room temperature were explored to find excellent electrical and optical properties. The lowest resistivity of the AZO thin films deposited at room temperature was 2.8 × Ω·cm, and the average transmittance in the 400-to-900-nm wavelength region was 93%. The optimized composition of the AZO thin film, which had the lowest resistivity and highest transmittance was Al0.05Zn1O1.05 (about 3.13-wt% Al₂O₃).