Performance of dye-sensitized solar cell (DSSC) using carbon black-TiO2 composite as counter electrode subjected to different annealing temperatures

Abstract

Carbon black-TiO2 composite counter electrode was synthesized via solid state method and subsequently annealed at different annealing temperatures (450–550 °C). The composite was investigated as a counter electrode, acting as an alternative to platinum in a dye-sensitized solar cell. The aim is to obtain a higher conversion efficiency of solar energy being converted into electricity. The synthesized sample was structurally characterized by X-ray diffraction and it was found that annealing temperature strongly enhanced the anatase structure of carbon black-TiO2. The surface morphology and grain size were examined by field emission scanning electron microscopy which showed the presence of mesoporous structure; this is very important for high quality dye and electrolyte distribution. Electrochemical studies of carbon black-TiO2 counter electrodes suggest that increasing the annealing temperature may lead to increased charge transfer resistance which could contribute to decreased catalytic activity. The photovoltaic properties of carbon black-TiO2 were observed to be strongly influenced by the annealing temperature; measurements taken at annealing temperature of 525 °C showed the best photovoltaic properties of JSC = 6.10 mA/cm2, VOC = 0.51 V, FF = 0.89 and η = 2.77%.