Spectrally narrowed emissions in single crystals of 2,5-bis(4-biphenylyl)thiophene

We have investigated the emission properties in 2,5-bis(4-biphenylyl)thiophene (BP1T) crystals, which show high emission yields and efficient excitation energy propagation, using nonlinear emissions such as spectrally narrowed emissions (SNE) and stimulated resonance Raman scattering (SRRS). The high emission yields and SNE can be explained by a model in which strongly emissive H-aggregates are formed. The observed SRRS is explained by the double resonance of incoming light and outgoing Raman line in this model.