The effect of SWCNT with the functional group deposited on the counter electrode on the dye-sensitized solar cell

This study investigated the applicability of single wall carbon nanotubes (SWCNT) with the functional group deposited on the FTO-glass (Fluorine doped tin oxide, SnO2:F) substrate of the counter electrode for a dye-sensitized solar cell (DSSC). A nanocrystalline TiO2 layer was fabricated on the FTO-glass substrate of the working electrode, and then sintered in a high-temperature furnace. The working electrode with a TiO2 thin film was immersed in the solution of N-719 (Ruthenium) dye for 12 h. Moreover, the counter electrode with a layer of Ag (or without a layer of Ag) and a layer of SWCNT, which were (or was) fabricated in that order on the FTO-glass substrate, was subsequently prepared. Finally, the DSSC was assembled, the power conversion efficiency of the DSSC was measured using an I–V measurement system, and the incident photo conversion efficiency (IPCE) of the DSSC was obtained using the phase-locked loop optical chopper. This study also examined the effects of a layer of Ag deposited on the FTO-glass substrate, the type of organic solvent (such as DMAC and acetylacetone), and the sintering temperature on the performance of the DSSC. This film of SWCNT/Ag markedly increased the IPCE from 3.9% (conventional DSSC with a thin film of platinum on the FTO-glass substrate of the counter electrode) to 15.3% (DSSC with SWCNT/Ag/acetylacetone), as the wavelength of the light was 380 nm. Furthermore, as the wavelength of the light is 550 nm, the IPCE of the DSSC with SWCNT/Ag/acetylacetone (6.8%) becomes nearly equal to that of conventional DSSC (7.2%). Most interestingly, this study shows that the power conversion efficiency of the DSSC with SWCNT/Ag/acetylacetone (1.3037%) is not inferior to that of DSSC with a thin film of platinum on the counter electrode (1.25%).