An efficient dye-sensitized solar cell using surfactant-modified mesoporous carbon film as a counter electrode

Mesoporous carbon (MC), prepared by the carbonization of phenol resin using ethylene glycol as a pore forming agent, was used as the catalyst of the counter electrode in dye-sensitized solar cells (DSCs) fabricated by a paste coating method at low temperature, where a non-ionic surfactant, Triton X100, was used as a modifier of the paste. Fractal dimensions (DF) were used to evaluate the morphological difference of the MC films on the substrate with surfactant content. The efficiency of the DSCs using the MC modified by the surfactant reaches a maximum of 5.65% for 0.6g MC with 0.1 mL surfactant. This is 46.5% higher than that of DSCs using activated carbon as a catalyst in the counter electrode, and 95.4% of the value obtained using DSCs with a Pt counter electrode under the same conditions. The performance improvement of the surfactant-modified MC counter electrode is attributed to a uniform MC film with a low DF value induced by adding the surfactant, a large average mesopore size of 34.6 nm that is favorable for mass transport, and a high-surface-area glassy carbon structure that has a high content of active sites.