Mg(OOCCH3)2 as an electrolyte additive for quasi-solid dye-sensitized solar cells: with the purpose of enhancing both the photovoltage and photocurrent by modifying the TiO2/dye/electrolyte interfaces

Abstract

The interface modification effect within quasi-solid dye-sensitized solar cells and the photovoltaic performance were investigated after the introduction of Mg(OOCCH₃)₂ as an additive into a polymer gel electrolyte. Electrochemical impedance spectroscopy showed that the addition of Mg(OOCCH₃)₂ into the polymer gel electrolyte can efficiently retard charge recombination at the TiO₂/electrolyte interface. Mg(OOCCH₃)₂ in the electrolyte can also contribute to the enhancement of the incident photon-to-electron conversion efficiency by modifying the dye molecules. This results in an improvement in the photovoltage and photocurrent due to a barrier layer at the TiO₂/electrolyte interface and the promotion of charge injection at the dye/TiO₂ interface, respectively. Photovoltaic measurements reveal that a conversion efficiency enhancement from 4.05% to 4.96% under 100 mW cm⁻² is obtained after the amount of Mg(OOCCH₃)₂ added was optimized.