Performance improvement of dye-sensitized solar cells by surface patterning of fluorine-doped tin oxide transparent electrodes

The surface modification of fluorine-doped tin oxide (FTO) transparent electrodes was carried out by lithography and inductively coupled plasma etching to improve the conversion efficiency of dye-sensitized solar cells (DSSCs). The concentration of Cl2 gas and dc-bias voltage to the substrate were varied as the main etch parameters. The transmittance and sheet resistance of the FTO electrodes were compared before and after etching. The DSSCs fabricated on the patterned FTO electrodes showed higher conversion efficiency than those fabricated on the ordinary FTO electrodes without patterns. Scanning electron microscopy showed that more TiO2 particles could be involved in the DSSCs with patterned FTO electrodes, and that the contact between the TiO2 layer and electrode were improved by patterning the FTO electrode. The current–voltage curves and incident photon to current efficiency spectra showed that a significantly higher photocurrent was produced in the DSSCs fabricated on the patterned FTO.