Conjugated polymers luminescence property

The active layer consists of a polymer having electronic conductive, ionic conductive, and luminescent properties, is blended with an ionic salt [48]. The polymer with the required properties can be realized by a blend of a conjugated and an ionic conductive polymer [481 or by specially designed polymers [71-73],... 

Ley and Schanze have also examined the luminescence properties of the polymers Pq, Pio> P25> and P50 in solution at 298 K, and in a 2-methyltetrahydro-furan solvent glass at 77 K. These spectroscopic studies reveal that fluorescence from the 71,71" exciton state is observed at Amax=443 nm, 2.80 eV in the polymers P0-P50 at 298 and 77 K, but the intensity and lifetime of the fluorescence is quenched as the mole fraction of Re in the polymers is increased. This indicates that the metal chromophore quenches the 71,71" state. The quenching is inefficient even when the mole fraction is large, suggesting that interchain diffusion of the 71,71" exciton is slow compared to its lifetime [70]. Phosphorescence from the 71,71" state of the conjugated polymer backbone is observed at > max=b43 nm, 1.93 eV in P10-P50 at 77 K, and emission at Amax=690 nm, 1.8 eV is assigned to the d7i(Re) 7i oiy MLCT transition. 

An important difference between luminescent conjugated polymers and laser dyes is that the former still exhibit strong optical gain in the solid state. This property means that luminescent conjugated polymers can be used to produce stimulated emission in thin films of these materials. 

Below, the one-dimensional band structure of simple linear conjugated polymers is outlined, followed by a brief description of the use of some model 7t-conjugated molecules for conjugated polymers. Then, to close out the chapter, the description of the properties of conjugated polymers is extended to issues of optical absorption and photo-luminescence. 

Rothe C, Guentner R, Scherf U, Monkman AP (2001) Trap influenced properties of the delayed luminescence in thin solid films of the conjugated polymer poly(9,9-di(ethylhexyl)fluorene). J Chem Phys 115(20) 9557—9562... 

PFs are a fascinating family of conjugated polymers. Their unique luminescence properties make them ideal model systems to study new physical phenomena in conjugated polymers at the single molecule level—effects which are usually masked in the ensemble photophysical studies, but are nevertheless absolutely crucial to determining the bulk material properties. 

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