Effect of white light irradiation on the systems Al/poly(4, 4-dipentoxy-2,2 '-bithiophene)/ITO and Al/SiO/poly(4,4 '-dipentoxy-2,2 '-bithiophene)/ITO

The electrical characteristics of the systems Al/poly(4,4'-dipentoxy-2,2'-b ithiophene)/ITO and of Al/SiO/poly(4,4'-dipentoxy-2,2'-bithiophene)/ITO wer e investigated in the dark and under white light illumination. It was found that a thin layer (similar to 0.4 nm) of silicon monoxide, at the interfac e between the conducting polymer and the aluminium electrode, is able to re duce the ion conductivity, induced by the formation of an aluminium hydroxi de layer, in the structure Al/poly(4,4'-dipentoxy-2,2'-bithiophene)/ITO. Th e photovoltaic parameters of the junction, hidden by photoelectrochemical p rocesses in the case without the SiO layer, were observed and discussed. A photosensitivity of the order of 10(-3) A W-1 was obtained under a reverse bias of -2 V, at low incident power irradiation. (C) 1998 Elsevier Science S.A. All rights reserved.