Improved performance of dye-sensitized solar cells with surface-treated TiO_2 as a photoelectrode

摘要

We report on the effects of surface-modified TiO_2 on the performance of dye-sensitized solar cells (DSSCs). TiO_2 surface was modified with Na_2CO_3 via a simple dip coating process and the modified TiO_2 was applied to photoelectrodes of DSSCs. By dipping of TiO_2 layer into aqueous Na_2CO_3 solution, the DSSC showed a power conversion efficiency of 9.98%, compared to that (7.75%) of the reference device without surface treatment. The UV-vis absorption spectra, the impedance spectra and the dark current studies revealed that the increase of all parameters was attributed to the enhanced dye adsorption, the prolonged electron lifetime and the reduced interfacial resistance.