Reflectance enhancement by multi-layered TiO₂/SiO₂ coating on stainless steel substrate for dye-sensitized solar cells

[TiO₂|SiO₂] multi-layer for the DSSC was fabricated to improve the light re-adsorption of the dye by the enhancement with the light reflectivity from the surface of stainless steel substrate. TiO₂ (H) and SiO₂ (L) thin films were deposited on the stainless steel substrate by RF magnetron sputtering at a high substrate temperature of 600°C and multi-layer structure of [air|(HL)₄|30₄SS] was fabricated. In order to estimate high reflection coating and the experimental results in advance, the simulation program, the Essential Macleod Program was adopted. SiO₂ thin film showed the low refractive index of 1. 6259 and TiO₂ thin film showed high refractive index of 2. 4722 at a wavelength of 633 nm measured by ellisometry measurement. The spectral reflectance of stainless steel increased up to around 75% by multi layer optical coating at a wavelength range of 400-550 nm.