Effect of annealing temperature in nitrogen atmosphere and under vacuum on structural, optical and electrical properties of sputtered ITO/Ni/ITO multilayer

ITO/Ni/ITO multilayers were deposited on glass substrates by RF sputtering. These multilayers were annealed at temperatures between 200 and 500 °C, under two different atmospheres: nitrogen gas (N2) and vacuum. Optical measurements show that the films treated under nitrogen gas, have a higher average transmittance in the visible range, which reaches 84% after annealing at 500 °C. While for vacuum annealed films, it reaches only 69%. However, for the electrical properties, the vacuum-treated films show better performance with an electrical resistivity of 1.42 × 10–4 Ω cm at the annealing temperature of 500 °C, which is much lower than that found in N2-treated films (5.54 × 10–4 Ω cm). Based on the figure of merit, it is found that the thin films annealed in N2 show better performance and the maximum reached was 2.3 × 10–2 Ω−1.