Conjugated polymers offer many advantages as materials for light-emitting diodes. They are mechanically flexible

and can be fabricated and patterned with relative ease by casting from solution

and the emitted light color of these semiconducting and luminescent polymers can be controlled by designing the molecular structure. Among the blue emitting materials

poly(paraphenylene) (PPP) and its derivatives are promising because of their high photoluminescence(PL) efficiency. The stability of PPP and the solubility of PPP with side groups are the focus of our concern. Four luminescent materials of conjugated copoly(phenylene-alkoxyphenylene)s were synthesized

all these polymers have excellent solubility in common organic solvents. The UV-Vis absorption spectra and the photoluminescence properties of their films and solvents were studied

and their energy band structures were inspected through electrochemical methods. The effect of alkoxy side chains on luminescence intensity of the polymers was discussed. The results showed that these four polymers emitted blue lights with excitation of UV rays

and energy values of π-π

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transition were within 3.2-3.3eV. The luminescence intensity reached the peak when the polymers had the alkoxy side chain with about 10 carbon atoms.