Improving Energy Conversion Efficiency of Dye-Sensitized Solar Cells by Modifying TiO2 Photoanodes with Nitrogen-Reduced Graphene Oxide

Abstract

As potential third generation photovoltaic cells, dye-sensitized solar cells (DSSCs) have attracted extensive research interests and have become one of the hot topics in current research. In this work, a series of DSSCs based on TiO2 photoanodes modified by graphene oxide (GO) and nitrogen-reduced graphene oxide (N-rGO) were fabricated. Results indicate that N-rGO is a better TiO2 photoanode modifier of DSSCs compared to GO. With an increase in the amount of N-rGO, the open circuit voltage increases, while both the short circuit current and power conversion efficiency (PCE) of the DSSCs exhibit a maximum at the content of 0.2 wt % N-rGO. In particular, the maximum PCE of the DSSCs reaches 7.19% in this work, which gains a 13.23% enhancement compared to the PCE of 6.42% of conventional TiO2 DSSCs. The enhancement of the PCE of the DSSCs with N-rGO was mainly attributed to the reduction in electron recombination and the increase in electron transfer efficiency after incorporating N-rGO into TiO2 photoanodes.