e., higher

light concentration). With the use of the condenser lens system, the PCE of the reference T25 SL-based DSSC was found to slightly decrease from approximately 3.57% (without the condenser lens) to approximately 3.38%, when the focal length was set to the maximum value of approximately 10 mm. This is owing to the increase of power input caused by higher light concentration with longer focal length. However, as the light concentration increased, both I sc and V oc Vistusertib were observed to make a significant increase. This is consistent with the general theoretical model given in Equation 1 for conventional inorganic solar cells that I sc increases linearly with increasing light intensity (X), and V oc increases logarithmically with increasing I sc and X: where, n is the diode quality factor, k is the Boltzmann’s constant, T is the absolute temperature, q is the electronic charge, and I o is the reverse saturation current. Table 1 Summary of photovoltaic characteristics of T25-accumulated single layer (T25 SL)-based

DSSCs Type Condenser lens Focal length (mm) Light concentration (Suns) I sc (mA) V oc (V) FF PCE (%) T25 SL Without – 1.00 2.53 0.69 0.74 3.57 With 6 2.12 5.27 0.73 0.69 3.47 7 2.44 6.01 0.73 0.68 3.41 8 2.78 6.95 0.73 0.67 3.41 9 3.24 8.14 0.74 0.66 3.40     10 3.72 9.35 0.74 0.65 3.38 I sc, photocurrent; V oc , open circuit voltage; FF, fill factor; PCE, power conversion efficiency. In order to examine the effect of the TiO2 light-scattering layer on the performance of DSSCs, we fabricated Ricolinostat supplier three different DSSCs with photoelectrodes LB-100 composed of (1) a T25/T25 DL, (2) T25/T240 DL, and (3) T240/T240 DL with a total thickness of approximately 18 μm. After the T240-accumulated light-scattering layer was applied on the T25 layer, the resulting PCE of the fabricated DSSCs without condenser lens improved from approximately 3.57% (i.e., T25-SL-based DSSC, Tau-protein kinase Table 1) to approximately 4.36% (i.e., T25/T240-DL-based

DSSC, Figure 2c), corresponding to an approximately 22% increment. This suggests that the T240-accumulated layer could play the role of dye molecule absorbing or light scattering or both. The former can be directly ascertained by examining the photovoltaic performance of the DSSC based on a T240/T240-DL-based photoactive layer as shown in Figure 2. Consequently, an I sc of 0.62 mA, a V oc of 0.75, a fill factor (FF) of 0.50, and a PCE of 0.64% were obtained for the DSSC based on the T240/T240-DL-based photoactive layer under a 1 sun condition at AM 1.5, indicating that the number concentration of photogenerated electrons is negligibly small and the role of the absorbing dye molecules in increasing the PCE in the pure T240-accumulated layer is relatively very weak. Therefore, the higher PCE obtained for the T25/T240-DL-based DSSC when compared with that of the T25-SL-based DSSC is a consequence of greater light scattering.