Energy migration and photon harvesting

Excimers can usually be detected by a shift of the fluorescence emission maximum to a wavelength longer than in the case of monomer emission. 

Ground state Monomer singlet Excimer singlet 

This process is evidenced by the anthracene fluorescence, which is quite distinct from that of naphthalene. The quantum yield of anthracene sensitization 

1(D) and 1(D) are the donor fluorescence intensities in the absence and in the presence of the acceptor, respectively. 0s values varying between 0.1 and 0.7 have been found by examining, in aqueous or organic solvents, a variety of polymers having naphthalene and anthracene groups attached to the main 

Chart 1.3 Chemical structures of repeating units bearing naphthalene and anthracene groups contained in copolymers employed in photon-harvesting studies [13]. 

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