| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1267537 | Organic Electronics | 2012 | 8 Pages |
The degree of charge transfer in thin films of organic charge transfer (CT)-complexes, which are deposited via thermal evaporation, is examined via infrared-spectroscopy. We demonstrate a linear relationship between the shift in the excitation energy of the CN-stretching mode of CT-complexes with the acceptor 7,7,8,8-tetracyanoquinodimethane (TCNQ) and the charge transfer. The measured correlation corresponds very well with DFT calculations. For Na-TCNQ we observe a splitting in the peak of the CN-stretching mode, which can be explained by the coupling of two modes and was confirmed by the calculations. In CT-complexes with partial charge transfer the appearance of an electronic excitation is demonstrated.
Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Linear relation between charge transfer and energy of the TCNQ CN-stretching mode. ► Splitting of CN-stretching mode in fully charged complexes due to mode coupling. ► Energy absorption band due to electronic excitation of partially charged complexes.
