Preparation and optimization of MTO/Ag/MTO transparent flexible film based on co-sputtering at room temperature

The transparent flexible SnO₂:Mo/Ag/SnO₂:Mo (MTO/Ag/MTO) triple-layer film was prepared based on co-sputtering at room temperature for the first time. The optimization of the MTO layer thickness on the optical and electrical properties of the triple-layer films was investigated and the bending stability was verified by bending test. It was found that the visible light transmittance of the triple-layer film increases first and then decreases with the increase of MTO layer thickness, which indicates that the MTO layer thickness plays an important role in optimizing the visible light transmittance of the triple-layer film. Also, as the thickness of the MTO layer increases, the triple-layer film carrier concentration decreases and the sheet resistance increases. Therefore, the triple-layer film with excellent properties was obtained via the optimization of the MTO layer thickness to 40 nm, which has a maximum figure of merit of 2.0 × 10^–2 Ω⁻¹, a high visible light transparency of 82% and a low sheet resistance of 6.9 Ω/sq. Meanwhile, the prepared triple-layer film also has excellent mechanical flexibility (curvature radius R ≥ 4 mm, and the number of bending times is 10,000).