MgO coated TiO2 nanoporous film for Dye sensitized solar cell

Abstract

In this study, MgO coated TiO2 core-shell film was obtained by using dip coating method and different types of solvents were used to see the effect of solvent on the photovoltaic properties of dye sensitized solar cell (DSCs). The MgO coated TiO2 electrodes had been characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), high-resolution transmission electron microscopy (HR-TEM), UV-vis spectroscopy, electrochemical impedance spectroscopy (EIS) and solar simulator. The study results revealed that when ethanol was used as a solvent, it showed faster growth rate than water and thicker shell was observed. More importantly, the amount of adsorbed dye was increased after MgO was coated on TiO2. When TiO2 was coated by dip coating in the precursor solutions of magnesium hydroxide which made up of 5 mM solution in DI water, short-circuit current (Jsc) , open-circuit voltage (Voc) and FF were increased. In contrast, if ethanol was used as a solvent, Jsc and electron life time was decreased but Voc and FF was increased. When TiO2 electrode was dipped into precursor solution with DI water for 2hr, the thickness of MgO shell was approximately 1nm. However, same thickness was achieved when electrode was dipped into solution made up of ethanol for 1 hr. Amount of dye adsorbed is same but photovoltaic performance was different. When shell was formed by dipped magnesium hydroxide precursor solution made up of DI water 2hr, Jsc was increased but Voc, FF were decreased compared with ethanol and electron life time was increased. As MgO shell gets thicker electron lifetime was decreased.