Photoinduced hole-transfer in nanoparticle-dye hybrid composites: a route for exciton dissociation leading to photovoltaic devices

Abstract

We present a hybrid nanocomposite system based on lead sulfide (PbS) quantum dots and a metal phthalocyanine derivative for photovoltaic devices. The composite has been chosen in such a manner that photoinduced hole-transfer from the quantum dot to the dye is energetically favorable. Photoluminescence of PbS nanoparticles quenched upon PbS:dye composite formation substantiating that such a hole-transfer occurred leading to dissociation of photogenerated excitons. The devices based on the PbS:phthalocyanine systems sandwiched between two electrodes have yielded photovoltaic characteristics. Short-circuit current of the devices has increased with an increase in concentration of the dye in hybrid nanocomposites. Since the devices are based on PbS quantum dots, they moreover have acted as NIR-active solar cells.