Low-Cost Dye-Sensitized Solar Cells Based on Interconnected FTO-Activated Carbon Nanoparticulate Counter Electrode Showing High Efficiency

The development of low-cost DSCs （Dye-sensitized solar cells） based on activated carbon counter electrodes is described. Although, the use of activated carbon in CEs （Counter electrodes） has been documented, the efficiencies obtained in such solar cells have been low, particularly, due to low electrical conductivity of such counter electrodes. Our design of the counter electrode eliminates this problem by using an in-situ formed FTO （Fluorine-doped tin oxide）-activated carbon composite on FTO surface as the CE. The FTO particles are prepared by atomized spray pyrolysis method from a spray solution containing dispersed activated carbon particles. The CE thus prepared has a reasonable electronic conductivity and the composition of the spray solution was optimized to give the highest conversion efficiency and the thickness of the CE was optimized by controlling the spray duration and deposition temperature. The best DSC based on AC-FTO CE has a Jsc of 18,98 mA.cm2, a Voc of 0.709 V, and a FF （Fill factor） of 0.563 giving a conversion efficiency of 7.6%. The data for Pt-FTO CE based DSC are a Jsc of 18.78 mA.cm2, a Voc of 0.732 V, and a FF of 0.688 with a conversion efficiency of 9.5%.