Ultraviolet-A-transparent aluminum-doped zinc oxide thin film electrodes by pulsed laser deposition

The optoelectronics industry eagerly demands high-performance and low-cost ultraviolet (UV)-transparent electrodes to increase the efficiency of UV devices. However, aluminum-doped zinc oxide (AZO) is rarely considered a candidate for UV-transparent electrodes. Herein, this work fabricates AZO films by pulsed laser deposition and shows the potential of these films as UVA (320-400 nm)-transparent electrodes with Haacke's figure of merit up to ∼3.23 × 10^-3 Ω^-1. A strong correlation is discovered between the UV transparency and the substrate temperature during the fabrication of AZO thin film electrodes. The AZO film fabricated with a substrate temperature of 500°C possesses an optical band gap of ∼3.86 eV, an average transmittance to UVA of ∼77.1%, and a sheet resistance of ∼23 Ω, demonstrating the high potential as UVA-transparent electrodes for high-performance optoelectronics.