National Research Council of Canada. Information and Communication Technologies
Oxide-Based Materials and Devices VI, February 8-11, 2015
Dye-sensitized solar cells; Hole mobility; Metallic films; Oxides; Printing; Printing presses; Sol-gel process; Sol-gels; Solar cells; Vanadium; Coordinating ligands; Hole transporting layers; Inverted organic solar cells; Organic solar cell; Power conversion efficiencies; Vanadium oxides; Oxide films
In this paper we report on the synthesis and development of vanadium oxide precursor flexographic ink for the printing of hole-transporting layers in organic solar cells. For the synthesis of vanadium oxide inks, a sol-gel methodology was utilized. By modifying the vanadium alkoxide precursor with a right type of coordinating ligands a stable and flexoprintable ink has been successfully developed. Flexo-printing afforded smooth and uniform vanadium oxide sol-gel films on top of PCDTBT:PC<inf>70</inf>BM films. The conversion of the synthesized sol-gel film into a corresponding vanadium oxide layer was followed by DSC/TGA and XPS analyses. The inks were used for the fabrication of inverted organic solar cells by flexo-printing. Power conversion efficiencies ranging between 3.5 % and 4.5 % were achieved, which are slightly lower than the reference cells using vacuum-deposited MoO<inf>3</inf> as the hole-transporting layers.