The different film thicknesses of graphite/carbon black on the counter electrodes by spray coating method for dye-sensitized solar cells

Composite carbon films of graphite and carbon black doped anhydrous ethanol were deposited on indium tin oxide (ITO) substrates. In this study, a spray coating method was used to deposit different thicknesses of the films on ITO substrates as a counter electrode for dye-sensitized solar cells (DSSCs). Scanning Electron Microscopy (SEM) was used to analyze the surface morphology of graphite/carbon black films, and Electrochemical impedance spectroscopy (EIS) was used to prove that the R_CT will be decreased by adding the carbon black. As the graphite/carbon black films thicknesses increased from 2.3μm to 10.4 μm, the contact area of the carbon electrode with the electrolyte was increased to enhance the catalytic activity. The energy converting efficiency of the DSSC device has been improved from 0.8 to 1.5 % by increasing the thickness of the graphite/carbon black counter electrode.