A comparative study of photoluminescence spectra of chromophores and semiconducting polymer films

Photoluminescence (PL) spectra of chromophore-attached polymer and semiconducting polymer thin films are comparatively studied. In the chromophore thin film, we clearly observe that a vibronic subband of the luminescence has been bleached after waveguiding under optical pumping, in strong contrast to the case of the semiconducting polymer film. This provides direct evidence that the PL mechanisms in short chromophores and semiconducting polymers are different.