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International Journal of Photoenergy
Volume 2011, Article ID 513089, 11 pages
Research Article

Characterization of the Pore Filling of Solid State Dye Sensitized Solar Cells with Photoinduced Absorption Spectroscopy

Solar Energy, Energy Research Centre of the Netherlands (ECN), Westerduinweg 3, 1755 LE Petten, The Netherlands

Received 15 October 2010; Revised 26 April 2011; Accepted 16 May 2011

Academic Editor: Dinko Chakarov

Copyright Š 2011 Carol Olson et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Near steady-state photoinduced absorption (PIA) and UV-Vis absorption spectroscopy are used to characterize the pore filling of spiro-MeOTAD (2,2,7,7-tetrakis-(𝑁,𝑁-di-𝑝-methoxyphenylamine)9,9-spirobifluorene) into the nanoparticulate TiO2 electrode of a solid-state dye-sensitized solar cell (ssDSC). The volumetric ratio of filled to unfilled pore volumes, as well as the optical signature of interacting chemical species, that is, the hole-transfer yield (HTY), are investigated. PIA spectroscopy is used to measure the HTY, relative to the amount of spiro-MeOTAD present, without needing to determine the extinction coefficients of the dye and spiro-MeOTAD cation species. The Beer-Lambert law is used to relate the relative PIA signal to the penetration length of the hole-conductor in the TiO2 film. For the sample thickness range of 1.4-5 μm investigated here, the optimum characteristic penetration length is determined to be 3.1+0.46 μm, which is compared to 1.4 μm for the 200 mg mL−1 concentration of spiro-MeOTAD conventionally used. Therefore, doubling the effective penetration of spiro-MeOTAD is necessary to functionalize all the dye molecules in a ssDSC.