Development of Dye-Sensitized Solid-State ZnO/D149/CuSCN Solar Cell

Abstract

Dye-sensitized solid-state solar cells (DSSC) based on n-type ZnO and p-type CuSCN have been fabricated with highest recorded power conversion efficiency. The working electrode of the cell is composed of D149 dye-coated ZnO -based interconnected nanoparticulate (20 nm) mesoporous layer with ZnO -based dense layer which was prepared on fluorine-doped tin oxide (FTO) glass substrates. CuSCN deposition was carried out according to the previously reported procedure which ensures enhanced p-type conductivity of CuSCN . The surface morphologies of the ZnO dense layer, ZnO porous layer and CuSCN layer have been visualized using scanning electron microscopy (SEM). The cells were fabricated with the configuration of FTO/ ZnO dense layer/ ZnO porous layer/D149/CuSCN/Graphite/Cr-coated FTO. Then the cells were characterized using I-V data as functions of the dense layer resistance (which is proportional to the thickness of the dense layer) and the porous layer thicknesses. The optimum dense layer is found to have 1500 Ω/□ sheet resistance. The cell with porous layer thickness of 9 μm at this dense layer resistance shows the maximum power conversion efficiency of 2.28%. The solar cell parameters of this optimized cell are an open circuit voltage of 0.55 V, a fill factor of 0.51 and a short-circuit current density of 8.2 mA cm-2.