An unconventional route to high-efficiency dye-sensitized solar cells via embedding graphitic thin films into TiO 2 nanoparticle photoanode

Abstract

Graphitic thin films embedded with highly dispersed titanium dioxide (TiO 2) nanoparticles were incorporated for the first time into the conventional dye-sensitized solar cells (DSSCs), resulting in a remarkably improved cell efficiency due to its superior electron conductivity. Massively ordered arrays of TiO 2 dots embedded in carbon matrix were fabricated via UV-stabilization of polystyrene-block-poly(4-vinylpyridine) films containing TiO 2 precursors followed by direct carbonization. For dye-sensitized TiO 2 based solar cells containing carbon/TiO 2 thin layers at both sides of pristine TiO 2 layer, an increase of 40.6% in overall power conversion efficiency was achieved compared with neat TiO 2-based DSSCs. Such a remarkably improved cell efficiency was ascribed to the superior electron conductivity and extended electron lifetime elucidated by cyclic voltammetry and impedance spectroscopy. © 2011 American Chemical Society.