A simple post-treatment with urea solution to enhance the photoelectric conversion efficiency for TiO2 dye-sensitized solar cells

摘要

Dye-sensitized solar cells (DSSCs) are performed using C3N4 post-treated TiO2 particles as photoanode materials. The photoanode materials were synthesized via a simple method by which a thin layer of C3N4 was coated onto the surface of TiO2 particles after the TiO2 was dipped in urea solution followed by calcination properly. The experimental results show that the photoelectric conversion efficiency of the TiO2 DSSCs is remarkably improved. The measurements of I-V characteristic along with the analysis of electrochemical impedance spectroscopy indicate that the C3N4 layer can expand the visible light absorption, suppress the recombination reaction of the e(-)-h(+) pair and increase both the open circuit voltage and the short-circuit photocurrent density. The mechanism of the improved performance of TiO2 DSSCs by C3N4 coating coating is proposed. The post-treatment method recorded in this work can be easily operated and achieve an enhanced photoelectric performance of DSSCs.