Microwave-Assisted Hydrothermal Synthesis of TiO2 Mesoporous Beads Having C and/or N Doping for Use in High Efficiency All-Plastic Flexible Dye-Sensitized Solar Cells

Submicrometer-sized TiO2 mesoporous beads with and without C or C-N doping were synthesized via a novel microwave-assisted hydrothermal process under various hydrothermal conditions. The doping was done simply through the addition of a steric agent of hexamethylenetetramine. The resulting beads were characterized for their materials properties. Selected TiO2 beads were then made into photoanodes on Poly(Ethylene Naphthalate) substrates using a spin-coating process. The thin film photoanodes were analyzed for their dye absorbing capability and optical absorbance. All plastic flexible dye-sensitized solar cells were then fabricated using the obtained photoanodes. The photovoltaic performance and the electron transport of the resulting cells were determined. We demonstrate that the doping gives not only enhanced photon-to-electron conversion efficiency but also improved solar conversion efficiency. The effects of doping on the cell performance are addressed. (C) 2013 The Electrochemical Society. [DOI: 10.1149/2.048303jes] All rights reserved.