Efficiency Improvement of the DSSCs by Building the Carbon Black as Bridge in Photoelectrode

In general, the dye sensitized nano solar cell (DSSC) uses nano metallic oxide as N-type semiconductor, e.g. nano TiO2, integrated with dye to build its photoelectrode. The applied dye in photoelectrode of DSSC helps the metallic oxide to expand its absorption spectra into visible spectrum. This work used nano carbon black (φ =22nm) as bridge between the TiO2 and the alizarin yellow. They three kinds of nano particles are connected each other and built in a triangular structure. The added carbon black caused rising conductive band of the nano TiO2 and helped excitated electrons of the alizarin yellow to reach higher energy level. Experiments used spray technique to build the nano TiO2 layer with ca. 67% light transmittance on the ITO glass as the semiconduction photoelectrode. The sintering process was 400°C for 60 mins. The carbon black and the alizarin yellow had been first mixed before the semiconduction photoelectrode was immersed. The results show that the photoelectric conversion efficiency of the improved DSSCs has ca. double increasement and its open circuit voltage increases from ca. 0.5V to ca. 0.6V. The short circuit current variation depends on added amount of the carbon black and received the result, the larger the added amount, the bigger the short circuit current.