Properties of working electrodes with diamond blends in dye sensitized solar cells

We prepared blocking layers by adding 0.0 ∼ 0.6 wt% nano diamond blends (DBs) to TiO₂ blocking layers to improve the energy conversion efficiencies (ECEs) of dye sensitized solar cells (DSSCs). TEM and micro-Raman spectroscopy were used to characterize the microstructure and phases of DBs, respectively. Optical microscopy and FE-SEM were used to analyze the microstructure of the TiO₂ blocking layer with DBs. UV-VIS-NIR spectroscopy was used to determine the absorbance of the working electrodes. A solar simulator and a potentiostat were used to determine the photovoltaic properties and the impedance of the DSSCs with DBs. From the results of the DBs analysis, we determined a 6.97 nm combination of nano diamonds and graphite. We confirmed that ECE increased from 5.64 to 6.48 % when the added DBs increased from 0.0 to 0.2 wt%. This indicates that the effective surface area and electron mobility increased when DBs were added to the TiO₂ blocking layer. Our results indicate that the ECE of DSSCs can be enhanced by adding an appropriate amount of DBs to the TiO₂ blocking layers.