Room temperature cold sprayed TiO2 scattering layer for high performance and bending resistant plastic-based dye-sensitized solar cells

High efficiency and flexibility of plastic-based dye-sensitized solar cells (DSCs) are the necessary prerequisites for industrial applications. In this study, light scattering layers are prepared to improve the efficiency and bending resistance of the plastic-based DSCs by both room temperature cold spraying (RTCS) and spray deposition (SD) method. The effect of the adhesion between the TiO scattering layer and TiO nanocrystalline (NC) layer on both the energy conversion efficiency and bending resistance of the plastic-based DSCs are investigated. Results show that both RTCS-TiO and SD-TiO scattering layers yield much higher light-reflecting ability than the TiO NC layer. However, the adhesion between the TiO scattering layer and TiO NC layer for the NC + RTCS cell is higher than the NC + SD cell. The better adhesion results in higher efficiency and better bending resistance for the NC + RTCS cell than the NC + SD cell. In addition, it is found that the increasing ratio of the energy conversion efficiency for the plastic-based DSCs through the introduction of TiO scattering layer decreases significantly with increasing the thickness of TiO NC layer. By using the TiO NC layer with an optimized thickness, a highest efficiency of 5.24% is achieved for the plastic-based DSCs using an RTCS-TiO scattering layer.