Strategy for Controlling the Electrical Conductivity of Indium Tin Oxide (ITO) Nanobranches

The electronic properties of indium tin oxide (ITO) nanobranches fabricated by electron beam evaporation are controlled using the following two methods: i) The growth direction of the rods and branches is controlled by an epitaxial relationship with a yttria-stabilized zirconia substrate. The aligned growth of ITO nanobranches causes low sheet resistance because of the high density and good connectivity of the branches. ii) Heterojunction metal-oxide nanoparticles are coated on the surface of the nanobranches to form a depletion region in the near surface for band bending. The morphology of the metal oxide also affects the electronic properties of the nanobranches. The sheet resistance of Fe2O3-coated nanobranches (Fe2O3: film shape) increases linearly with the number of coatings. In the case of Mn2O3 (Mn2O3: nanoparticle shape), the sheet resistance is dramatically increased and saturated with the increase in the number of coatings.