The transportation path via the CB of graphene is in addition to

The transportation path via the CB of graphene is in addition to the traditional path. Owing to the excellent electrical conduction of the graphene, the graphene layer bridges behave as a channel for transferring electrons and rapidly transport the photoexcited electrons [22]. The graphene is homogeneous throughout the system, and the excited electrons are captured by the graphene without any obstruction. The collected electrons can be rapidly and effectively transported to the CB of TiO2 through graphene bridges. In the interface of graphene and TiO2, the resistance through

which charges are transported is reduced relative to the DSSC without graphene bridge and the recombination and back-reaction processes are suppressed. Figure 5 Energy level diagram and mechanism of photocurrent generation in Blasticidin S ic50 DSSCs with TiO 2 /graphene/TiO 2 sandwich structure. Figure  6 plots the photovoltaic performance of the DSSCs that were fabricated with the traditional structure and the sandwich structure on ITO substrate. Table  1 summarizes Tariquidar the photovoltaic parameters of these fabricated DSSCs. The model used to calculate shunt resistance (R sh) and series resistance (R s) is taken from [23]. Clearly, the DSSCs with the sandwich structure have higher photoelectrical conversion efficiency (3.93%) than those with the

traditional structure (2.46%). This improvement in photoelectrical conversion efficiency in the DSSCs arises mainly from increases in J sc and V oc. The sandwich structure also slightly increases FF. The recombination of the electrons is suppressed and an additional path for the transportation of photogenerated electrons is available, increasing J sc. Moreover, the photoelectrodes with the TiO2/graphene/TiO2 sandwich structure have a smaller absorption edge, as presented in Figure  3, so the DSSC with the TiO2/graphene/TiO2 sandwich structure can absorb light over a wide range of wavelengths and, therefore, has a higher V oc. Figure 6 Photovoltaic performance of DSSCs fabricated

with different structures. Table 1 Photovoltaic parameters of DSSCs fabricated with different structures Sample label J sc (mA cm -2) V oc (V) FF η(%) R sh (Ω) R s (Ω) 1 4.46 0.56 0.55 1.38 9,888 1 2 8.044 0.55 0.56 2.46 7,785 1 3 11.22 0.6 0.58 3.93 7,558 3 Conclusions This work proposed a simple and Methocarbamol convenient method to enhance the performance of DSSCs using a low-cost and easy fabrication process. DSSCs with three structures were fabricated, and the characteristics of these DSSCs, including the J sc, V oc, and photoelectrical conversion η of these DSSCs, were investigated. Clearly, the induced graphene film and sandwich structure markedly improve the performance of the DSSCs. This improvement in performance is associated with an increase in the absorption of light, a wide range of absorption wavelengths, shorter charge transportation distances, and the https://www.selleckchem.com/products/nepicastat-hydrochloride.html suppression of charge recombination when the graphene is applied.

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