Conjugated polymers color generation

The emission process in conjugated polymers occurs from neutral excited states, which are intrachain singlet excitons in most cases. They are generated either by direct photoexcitation or by recombination processes from other excited (band) states. The emission process is determined by the probability for the radiative transition from the excited state to the ground state. The emission color then depends on the shape and the energetic position of the emission spectrum. The same excited species are responsible for EL and PL emission therefore, the intrinsic components of their spectra are identical (see previous sections). 

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