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Light emitting polymers (LEPs) are poised to become the predominant display technology within this decade. Charge transfer materials (CTMs) within these LEPs are important as they aid the efficiency of the electroluminescence emitted from the devices. Since many of these materials are strong Raman scatterers, Raman microscopy would provide an ideal method for investigating CTMs in-situ in the polymer matrix. The Raman spectra of the widely used CTMs based on triphenylamines are assigned for three different substituted monomers and for selected dimers and trimers. Theoretical calculations using the hybrid BPW91 functional and split-valence polarised 6G(d) basis set were performed, and the Raman scattering frequencies calculated and compared with those from experimental materials. A good correlation was found between the computed and experimental frequencies for the monomers. The largest deficit was 29 cm −1 for any clearly assigned band, and there was an average error of 9.4 cm −1 for the five most intense bands. The experimental Raman spectrum of the dimer dimethyltriphenyldiamine (DMTPD) and the calculated Raman active vibrations of methyltriphenyldiamine (MTPD) show few significant changes compared to the monomer. Comparison of the experimental trimer spectra with monomer calculations also show that simplified DFT calculations may confidently be used for assigning many bands in larger polymeric CTMs.

Understanding the changes that occur when dyes are absorbed onto paper is crucial for the design of new inkjet dyes. This problem is particularly difficult for black dyes that have complex chromophores, and as a result, spectroscopic information on electronic and structural changes can be of importance. Surface-enhanced resonance Raman scattering (SERRS) and electronic structure calculations were used to probe in situ changes in the chromophore in black di-azo dyes printed onto paper. The data indicate that the low-energy chromophore is due mainly to the hydrazone group and the high-energy chromophore to both the azo and hydrazone groups. A comparison of SERRS from the dyes adsorbed onto silver particles in suspension and from the dyes on paper demonstrated a broadening of the chromophore into the red for both dyes and evidence of a structural change in one dye.