The effect of the side group, employed during synthesis, on the PL (photoluminescence), EL (electroluminescence) profiles and the light intensity of PPV derivatives has been investigated using MEH (methoxy-ethyl hexyloxy) and MCHM (methoxy-cyclo-hexyl-methyloxy) as side groups. The measurements show that even the most subtle change in molecular structure of PPV has a marked improvement on the EL, PL profiles and the light emission intensity. It has been found that the PL and EL intensities of the MCHM-PPV are higher than those of MEH-PPV. MCHM-PPV also demonstrated higher light emission at lower potentials and currents.