Investigation of the Stability of the Ruthenium-Based Dye (N719) Utilizing the Polarization Properties of Dispersive Raman Modes and/or of the Fluorescent Emission

Søren Hassing, Kit D. Jernshøj, Nguyen Tuyet Phuong, Torben Lund

Publikation: Bidrag til tidsskriftTidsskriftartikelpeer review

Abstract

Dye-sensitized solar cells (DSCs) offer intriguing new possibilities with the integration of these into, e.g., power generating windows or facade applications. For the DSCs to constitute a viable investment, the thermal appliance with respect to the working conditions typically encountered must be considered. One of the aspects governing the long-term thermal stability of the DSC is the dye stability and hence whether or not the dye is degraded upon heating or illumination. This emphasizes the need for a sensitive and nondestructive measuring technique with which it is possible to distinguish between a dye and the degradation products possibly formed in a DSC under working conditions. We have carried out the preliminary steps in this direction by showing that a distinction between the commonly used dye N719 and the main degradation product [Ru(LH)2(NCS)(4-tert-butylpyridine)][N(Bu)4] (N719-TBP for short) is possible by exploiting a combination of the polarization properties of the dispersive Raman modes with the small spectral change in the visible absorption spectrum and/or the difference in the polarization of the fluorescence related to the difference in molecular configuration. By measuring the polarized resonance Raman spectra in the region 650−1900 cm−1 it is demonstrated that the polarization dispersion is sufficient for four (1021, 1060, 1313, and 1606 cm−1) out of ten Raman modes to discriminate between N719 and N719-TBP. It is also demonstrated that the difference in molecular configuration between N719 and N719-TBP gives rise to an even larger change in the polarization of the fluorescence in the same spectral region. It therefore follows that a discrimination between the dye and degradation product can be based on the changes observed in the polarization properties of both the Raman as well as the fluorescence spectra
OriginalsprogEngelsk
TidsskriftThe Journal of Physical Chemistry Part C
Vol/bind117
Udgave nummer45
Sider (fra-til)23500-23506
Antal sider7
ISSN1932-7447
DOI
StatusUdgivet - 2013

Citer dette