Photovoltaic properties of TiO₂-based solar cells with sodium ethanesulfonate-modified photoelectrodes

ABSTRACT

Effects of sodium ethanesulfonate (SES) adsorbed on photoelectrode surface on the performance of dye-sensitized solar cells (DSSCs) was investigated. SES-modified photoelectrode was prepared by soaking the TiO₂ film to an aqueous SES solution for 20 min. The DSSC with SES-modified TiO₂ layer showed an increase in open circuit voltage (V_oc), short circuit current (J_sc) and fill factor (FF), resulting in a power conversion efficiency of 11.20%, compared to that of reference device with bare TiO₂ (10.21%). Electrochemical impedance spectroscopy and open circuit voltage decay measurements revealed that the SES modification of TiO₂ surface led to a longer electron lifetime by the suppression of the interfacial charge recombination between photo-injected electrons and I₃⁻ ions, resulting in an increase in J_sc and V_oc, compared with those of a reference device without surface modification.

KEYWORDS:

• Dye-sensitized solar cells
• electron lifetime
• photoelectrode
• recombination
• sodium ethanesulfonate

Funding

This research was financially supported by the Ministry of Education (MOE) and National Research Foundation of Korea (NRF) through the Human Resource Training Project for Regional Innovation (No. 2015H1C1A1035619). This research was also supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT and Future Planning (NRF-2016R1A2B1015037).