Interconnected TiO 2 nanowire networks for PbS quantum dot solar cell applications

Abstract

We present a simple method for the fabrication of an interconnected porous TiO 2 nanostructured film via dip coating in a colloidal suspension of ultrathin TiO 2 nanowires followed by high-temperature annealing. The spheroidization of the nanowires and the fusing of the loosely packed nanowire films at the contact points lead to the formation of nanopores. Using this interconnected TiO 2 nanowire network for electron transport, a PbS/ TiO 2 heterojunction solar cell with a large short-circuit current of 2.5mA/cm 2, a V oc of 0.6V, and a power conversion efficiency of 5.4% is achieved under 8.5mW/cm 2 white light illumination. Compared to conventional planar TiO 2 film structures, these results suggest superior electron transport properties while still providing the large interfacial area between PbS quantum dots and TiO 2 required for efficient exciton dissociation. © 2012 Fan Xu et al.