Enhancing the Photovoltaic Performance of Dye-Sensitized Solar Cells by Modifying TiO_2 Photoanodes with Layered Structure g-C_3N_4

摘要

The layered structure graphitic carbon nitride (g-C_3N_4) makes it possible to form good interfacial contact with metal oxide nanoparticles. In this paper, we obtain the TiO_2/g-C_3N_4 (TC) composite via ultra-sonication and apply it as photoanode materials in dye-sensitized solar cells (DSSCs). The TC photoanodes decrease the energy barrier of electron transport and improve the injection efficiency of photo-generated electrons. Moreover, the g-C_3N_4 broadens the absorption spectrum of the TiO_2 based photoanode to visible region and enhances the light harvesting. As a result, the short-circuit current density (J_(sc)) and power conversion efficiency (PCE) of DSSCs based on TC photoanode have been considerably increased from 9.75 mA/cm~(-2) to 11.29 mA/cm~(-2), 3.87% to 4.51%, compared with pure TiO_2 photoanode, enhanced by 15.8% and 16.8%, respectively.