In situ growth of novel laminar-shaped Co3S4 as an efficient counter electrode for dye-sensitized solar cells

Laminar cobalt sulfide (Co3S4) nanosheets are successfully deposited on fluorine doped tin oxide (FTO) substrates by a facile one-step hydrothermal method. When it was applied to dye sensitized solar cells as the counter electrode (CE), the laminar Co3S4 electrode, consisting of interconnected nanosheets, exhibits prominent catalytic activity and outstanding metallic conductivity. It is the special structure that facilitates the electron transfer and reduces interface resistance. Under one sun (100 mW cm−2) illumination, the dye-sensitized solar cell with the Co3S4 CE shows comparable photovoltaic conversion efficiency (Eff = 7.19%) to that with a Pt CE (Eff = 7.27%). The results indicate that the in situ hydrothermal method and the prepared novel laminar Co3S4 CE has potential for developing low-cost and high-efficient counter electrodes.