Characterization of the Pore Filling of Solid State Dye Sensitized Solar Cells with Photoinduced Absorption Spectroscopy
Figure 6
Photoinduced absorption spectra of (a) dye Z907 in TiO2 (◯), and [70]PCBM blended with spiro-MeOTAD on TiO2 (■, multiplied with a factor of 40); (b) TiO2 sensitized with dye Z907, with spiro-MeOTAD, normalized at the peak at 1400–1500 nm (0.83–0.89 eV), using spiro-MeOTAD concentrations of 25 (□),45 (∙), 90 (▵), and 180 (▾) mg mL−1; (c) spectrum of a ssDSC: sensitized (Z907) TiO2 infiltrated with a high concentration of spiro-MeOTAD (200 mg mL−1), (▵); compared with the spectrum of the spiro-MeOTAD/PCBM blend, (■). Spectra were recorded using excitation wavelengths of 514 nm (a, c) and 458 nm (b, c). (d) Frequency-dependent PIA intensities for TiO2 samples sensitized with dye Z907, infiltrated with 45 (■) or 180 (▴) mg mL−1 spiro-MeOTAD solution. The measurements were recorded at 1.05 eV (1180 nm). The solid lines are fits to the data (13) and result in steady-state lifetimes of 115 and 995 μs for the low and the high spiro-MeOTAD concentration, respectively.
