The effects of annealing temperature on the characteristics of carbon counter electrodes for dye-sensitized solar cells

The carbon films have been deposited by unbalanced magnetron sputtering (UBMS) at room temperature. The deposited carbon films have been post-annealed at temperatures ranging from 400 °C to 600 °C in increments of 100 °C using rapid thermal annealing equipment in vacuum ambient. The variations in microstructure, surface and electrical properties of carbon films with various annealing temperature were investigated by using Raman spectroscopy and X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and hall-effect measurement. In this paper, we proposed that annealed carbon films as the counter electrode in a dye-sensitized solar cell (DSSCs). We investigated the electrical performance of DSSCs using carbon counter electrodes prepared with various annealing temperatures. For the DSSC using the annealed carbon counter electrode prepared at 600 °C annealing temperature, we obtained the best performance of Jsc = 10.57 mA/cm2, Voc = 730 mV, FF = 64.9%, and η = 5.0%.

► The carbon films were prepared at room temperature by unbalanced magnetron sputtering system and annealed with increasing annealing temperature.
► The annealed carbon films had good conductivity and rough surface.
► The power conversion efficiency in DSSC using carbon counter electrode were improved due to the enhancement of the electrical properties of carbon electrodes annealed with increasing annealing temperature.