Conformations have a large impact on the optoelectronic properties for conjugated polymers.The conformations and electronic states as well as optical characteristics of MEH-PPV chains in solid solution

dilute solution

film and nanopore have been investigated with PLand PLEspectra The following conclusions have been obtained.The MEH-PPV chains are separated basically in THF tetrahydrofuran dilute solution.The MEH-PPV chains are aggregated basically in MEH-PPV solid film.There are two conformations of MEH-PPV chains

separated and aggregated conformations

in MEH-PPV/PS solid solution.The aggregated conformation of MEH-PPV increases with increase of MEH-PPV density in MEH-PPV/PS polystyrene solid solution.The MEH-PPV chains form chains bunch in nanopores of porous anodic alumina template.The electronic state and optical characteristics are different for separated and aggregated MEH-PPV chains as well as MEH-PPVbunch.The electronic energy band and the band width of PLE spectra are the widest

and then the energy positions of PL spectra peaks are lowest(about 594 nm) for the aggregated conformation states.On the contrary

the electron energy band and the band width of PLE spectra are narrowest

and then the energy position of PL spectra peaks are highest for the separated conformation states.