Efficient and stable back-illuminated sub-module dye-sensitized solar cells by decorating SiO2 porous layer with TiO2electrode

Abstract

The present study focuses on enhancing the efficiency of back-illuminated dye-sensitized solar cells (DSCs) by incorporating a SiO₂ mesoporous layer on a TiO₂ electrode. The performance of the DSCs is investigated by incident photon conversion efficiency (IPCE) and electrochemical impedance spectroscopy (EIS). It is observed that the photocurrent increases when the TiO₂ electrode is coated with a SiO₂ layer, resulting in an increase in the incident light to the dye–TiO₂ electrode, especially in the wavelength range 400–600 nm. The TiO₂ electrode coated with 500 nm diameter mesoporous SiO₂ exhibits better device performance than that using 100 nm diameter SiO₂ particles. With this modification, the Ti foil-based flexible sub-module DSC (5 cm × 10 cm) shows a high conversion efficiency of 7.13% under illumination of 100 mW cm⁻² (AM 1.5), as well as good stability.