Impedance spectroscopic study on hybrid phthalocyanine/lead sulphide nanocomposite film

Abstract

A unique organic/inorganic nanocomposite of non-aggregated lead sulphide (PbS) quantum dots (QDs) dispersed within a spun film of non-peripherally octakis(hexyl)-substituted metal-free phthalocyanine (C6H2Pc) has been prepared at room temperature by a simple and low-cost method. The frequency response of alternating current (AC) conduction in a 130 nm thick C6H2Pc/PbS film sandwiched between the indium-tin-oxide (ITO) and aluminum (Al) electrodes is found to obey the universal power-law. The cryogenic study of AC conduction reveals that the correlated barrier hopping (CBH) model closely fits to the experimental data at temperatures below 240 K. The parameters obtained by fitting the CBH model point out that the hopping process cannot take place directly between neighboring PbS QDs but involves the localized states within the matrix.