Tailored Air Annealing Strategy to Promote the Photoelectric Performance of AZO-Based Multilayer Films

We investigated the effects of air annealing on the photoelectric performance of aluminum-doped zinc oxide (AZO)/Al₂O₃/Ag/AZO. Transparent conductive films (TCFs) of AZO (55 nm)/Al₂O₃ (1.5 nm)/Ag (10 nm)/AZO (55 nm) were deposited on glass substrates via RF/DC magnetron sputtering at room temperature. The Al₂O₃ seed layer was proved to promote Ag wetting in the multilayers structure. The result shows that the optimum annealing condition for the multilayer film was determined as annealing for 30 min at 300 °C. The smooth surface obtained effectively reduced the light absorption and scattering, and the Ag layer with continuous growth and a high degree of crystallization contributed to the conductivity. The films exhibited a sheet resistance of 5.80 Ω/sq, an average transmittance of 93.43% in the 400–800 nm range, and a figure of merit (FOM) that was enhanced by 26.9% to 87.3 × 10^–3 Ω^–1 via air annealing. Remarkably, this is the highest FOM reported for analogous TCFs with an AZO/Ag/AZO configuration. The TCFs of this structure prepared by our method have potential applications in photovoltaic devices.