Electrospun TiO_2 nanowires for hybrid photovoltaic cells

摘要

A simple and controllable fabrication of TiO_2 nanowires by electrospinning and their applications to the electron transporting layer for hybrid organic-inorganic photovoltaic cells are reported. TiO_2 nanowires were directly electrospun onto an indium tin oxide on glass substrate from a solution in methanol of polyvinylpyrrolidone, titanium(IV) butoxide, and acetylacetone. The nanowire electrode obtained was consequently subjected to calcination at 450 °C. Solution of blended [6,6]-phenyl-C_(61)-butyric acid methyl ester and poly(3-hexylthiophene) was spin coated on the TiO_2 nanowire electrode, followed by thermal annealing and deposition of Au electrode. Hybrid organic-inorganic photovoltaic cells made of TiO_2 nanowires exhibited remarkable improvement of the cell efficiencies in terms of photocurrent density and open-circuit voltage as compared with those of references, TiO_2 flat films. Maximum energy conversion efficiency of hybrid organic-inorganic photovoltaic cells made of TiO_2 nanowires of 1.27% was achieved.