Thickness dependence of device parameters in solid state dye sensitized solar cells

Abstract

A solid-state dye-sensitized solar cell (SDSC) was fabricated with a very thin (~650 nm) mesoporous TiO2 electrode and a donor-antenna (D-A) dye by using 2,2′,7,7′-tetrakis-(N,N-di-p-methoxyphenyl-amine) 9,9′-spirobifluorene (Spiro OMeTAD) as hole conductor. A highly transparent thin electrode sensitized with D-A dye showed a short circuit current (Isc) of 4.10 mA/cm2, an open circuit voltage (Voc) of 782 mV and an efficiency of 1.79 % at an illumination intensity of 100 mW/cm2 (1 sun, AM 1.5G). TiCl4 treatment of mesoporous TiO2 layer resulted in Isc of 6.18 mA/cm2, Voc of 737 mV and an efficiency of 2.12% at the same illumination intensity. This investigation demonstrates the possibility of fabrication of SDSC by way of using a very thin and transparent TiO2 electrode together with a high molar extinction coefficient D-A dye, and the effect of TiO2 layer thickness on solid-state solar cell performances is discussed.