A hybrid structure of Mn (2.59 wt.%) doped SnO₂ (MTO)/Ag/MTO films with refractive index matching layers (IMLs) was deposited on PET substrate by a RF/DC magnetron sputtering method at room temperature. To match the refractive index (n) of MTO/Ag/MTO/PET film, high and low refractive index materials of MTO (n = 2.02) and SiO₂ (n = 1.52) were placed between MTO/Ag/MTO and PET substrate, respectively. In order to evaluate the effect of IMLs on the reflectivity and color variation, an optical simulation program, Essential Macleod Program (EMP) was adopted, in advance. From EMP simulation, the multilayer film of MTO (40 nm)/Ag (13 nm)/MTO (40 nm) with optimized IMLs of SiO₂ (120 nm)/MTO (10 nm) shows the excellent optical transmittance above 86.1% at the 550 nm wavelength, and the pattern visible defect was reduced as compared with the reference film of MTO/Ag/MTO/PET film without IMLs. From the bending test, the multilayer film of MTO (40 nm)/Ag (13 nm)/MTO (40 nm)/SiO₂ (90 nm)/MTO (10 nm)/PET showed excellent flexible properties. There was only 10% resistance variation under 10,000 bending cycle with curvature radius of 5 mm

Keywords: TCO, OMO structure, EMP simulation, Reflectance difference, Yellow-blue color difference