Thin Film ZnO Coated on FTO/TiO2 as an Anti Reflection Coatingfor EnhancingVisible Light Harversting in Dye Sensitized Solar Cells System

Abstract

ZnOmaterial has unique electrical and optical properties that many important applications, including as an anti-reflection coating in dye sensitized solar cells. Flat anti-reflective coatings (ARC) made of ZnO on top to improve the optical properties of the coating. In this study, ZnO nanoparticle were coated with TiO₂ nanolayers by a simple wet chemical route. TiO₂ nanorods coated ZnO nanoparticle was synthesized by two step i.e. (1) base hydrolysis and polymerization of TiO₂ (2) ZnO nanoparticle were coated with a TiO₂ layer. The TiO₂ coated ZnO prepared was characterized by X-ray diffraction (XRD), Reflectance spectroscopy, SEM and TEM. ZnO annealed at a temperature of 400^oC have the greatest crystal size than annealedat a temperature of 500 °C and 600 °C. While, the Reflectance (%R)properties shows that the higher annealing temperature of ZnO preparations, the higher of %R value of ZnO thin layer. The ZnO prepared by annealed at 400^oCgain a good performance of the lowest reflectance value. The difference properties are due to differences of light scattering resulting from the crystal size effect. The crystals size that have a good performance as an anti-reflection is around 20 nm, result study of ZnOannealed at 400 °C. TEM nanograph shows that the synthesized ZnO have spherical morphology. The optimum performance ofDSSCs was conducted using the photoanode ZnO-coated TiO₂at present 10%APTMS as surface modifier anchor dye group. Bythe addition of ARC we have been capable improve cell performance so that cells achieve an efficiency of 1.13%.