ARTICLE pubs.acs.org/JPCC
Femtosecond Decay and Electron Transfer Dynamics of the Organic Sensitizer D149 and Photovoltaic Performance in Quasi-Solid-State Dye-Sensitized Solar Cells M. Fakis,*,† E. Stathatos,‡ G. Tsigaridas,† V. Giannetas,† and P. Persephonis† † ‡
Department of Physics, University of Patras, 26504 Patras, Greece Department of Electrical Engineering, Technological and Educational Institute of Patras, 26334 Patras, Greece
bS Supporting Information ABSTRACT: In this work, the femtosecond upconversion spectroscopy was used for the study of ultrafast decay and electron transfer dynamics of the very promising all-organic sensitizer indoline dye, D149, in inert environments as well as on TiO2 substrates. The inert environments were toluene and acetonitrile solutions as well as poly(methyl methacrylate) (PMMA) films and Al2O3 nanostructured substrates. These were used to investigate relaxation and aggregation induced decays. TiO2 substrates were used to probe interfacial electron transfer dynamics. The excitation was at the S2 band while the dynamics of both S2 and S1 bands were detected. The dynamics of the S2 band in solutions and PMMA film, show a rapid S2S1 internal conversion, ranging from 0.20 to 0.45 ps depending on the environment. This component becomes < ∑ An exp t + A¥ , t g 0 τn ð1Þ FðtÞ ¼ n¼1 > : 0, t
