Performance Improvement of Dye-Sensitized Solar Cell by Surface Patterning of FTO Transparent Electrode

초록

As a method of increasing the conversion efficiency of dye-sensitized solar cells, the surface structure of transparent conducting oxide has been modified. Fluorine-doped tin oxide (FTO) has been used as a transparent conducting oxide and prepared on glass substrate. FTO electrode has been patterned using lithography and etched by inductively coupled plasma reactive ion etching. The pattern shape and dimension can be designed by lithography process. First of all, the etch rate of FTO electrode was examined by varying various etch parameters such as the concentration of etch gas, rf power, dc-bias voltage to substrate, and gas pressure. The FTO electrode has been patterned with fine geometries of line and space (1, 5, 10, 50, 100 mm). The physical, optical and electrical properties of patterned FTO electrode are investigated and compared with unpatterned FTO films. The optimal etching condition has been developed in order to minimize the etching damage on FTO electrode. Finally, the conversion efficiencies of the edd fabricated with unpatterned and patterned FTO electrodes were compared. At present, the improvement of approximately 20%~30% in cell efficiency has been confirmed.