Steady state photoconductivity of poly(2-styryl-1, 4- phenylene vinylene) (PSPV)

The steady state photoconductivities of poly(2-styryl-1,4-phenylene vinylene) (PSPV) and its oxidized form poly(2-methoxy-5-styryl 1, 4-phenyIene vinylene) (PMSPV) are studied. PSPV contains styryl radical in PPV backbone chain. The spectral response of the photocurrent of PSPV shows a peak at 2.7 eV with no additional peak structure near 2.4 eV. PMSPV made by the substitution of methoxy radical to PSPV shows somewhat unusual feature. The spectral response of PMSPV does not show any peak near the absorption edge and the magnitude of the photocurrent is decreased compared to that of the PSPV. The results are discussed in terms of the different interchain distances of the two polymers as well as the existence of a conjugated double bond in the styryl radical in these PPV derivatives.