Improving efficiency of dye-sensitized solar cell by modification of titanium dioxide electrode

Abstract

Dye-sensitized solar cell (DSSC) was constructed using titanium dioxide as anode electrode layer. titanium dioxide electrode layer was prepared from ultrasonic spray coating of titanium dioxide sol, which was synthesized from a sol-gel nethod. First, preparation parameters for titanium dioxide electrode layer (i.e., number of coats of titanium dioxide and sintering temperature) were varied. The highest efficiency for DSSC was obtained when the number of coats of titanium dioxide was 150 and sintering temperature for titanium dioxide layer was 150 degrees Celsius. Next, titanium dioxide electrode layer was modified by addition of scandium and vanadium, resulting in lower efficiency of DSSC. Titanium dioxide electrode layer was also modified by addition of tetracyanoquinodimethane (TCNQ). The solar cells with TCNQ modified titanium dioxide electrode was sintered at 250 degrees Celsius and exhibited the highest efficiency at 2% (w/w) TCNQ in titanium dioxide. Finally, the solar cells with TCNQ modified titanium dioxide electrode was sintered at 400 degrees Celsius, which ex ceeded decomposition temperature of TCNQ, resulting the presence of hollow spaces in place of TCNQ. The solar cells with titanium dioxide electrodelayer modified by hollow spaces exhibited the highest efficiency at initial concentration of TCNQ added of 9% (w/w) TCNQ in titanium dioxide.