Three-Dimensional Nanobranched Indium-Tin-Oxide Anode for Organic Solar Cells

A nanostructured three-dimensional (3D) electrode using transparent conducting oxide (TCO) is an effective approach for increasing the efficiency of optoelectronic devices used in daily life. Tin-doped indium oxide (ITO) Is a representative TCO with high conductivity and a high work function for anode applications. This paper reports the fabrication of a large-area ITO nanostructure with a branch shape using an electron beam evaporation process at temperatures as low as 80 C, which was free of any carrier gas and catalyst. The large surface to volume ratio in the anode by the ITO nanobranches increases both the hole mobility by a 3D pathway and light absorbance by scattering, resulting in organic solar cells with a 12% Increase In photocurrent and 20% photoconversion efficiency based on the bulk heterojunctlon of P3HT [region-regular poly(3-hexylthiophene)] and PCBM [phenyl-C61-butyric add methyl ester].