Multifunctional n-ZnO/p-NiO Nano-heterostructures: A novel Approach

N. Hullavarad, S. Hullavarad
University of Alaska Fairbanks, US

Keywords: multifunctional nanostructures, selective growth

Summary:

As miniaturization of electronic devices progresses, there is a need for innovation in materials, processes, systems and circuit designs that are robust, operate at low power and have multifunctionality. Large surface areas and quantum confinement effects in small dimensional nanoscale materials lead to unique properties (electronic, optical, chemical and thermal etc.) and their coexistence in one material that is not normally observed in bulk materials. These unique properties can be exploited to make devices that allow extreme miniaturization and enhanced functionality. In this paper, we demonstrate the selective area growth of ZnO nanowires by self catalyst method. Nanomaterials based on ZnO are extremely attractive due a direct optical band-gap (Eg = 3.37 eV) material with a large exciton binding energy (60 meV), exhibiting near UV emission, and tunable for transparent conductivity and piezoelectricity. The ZnO nanowires are grown on p- Si and NiO (inherently p-type) to form the heterostructures. The nano-heterostructures are used to fabricate multifunctional sensors. The heterostructures exhibit excellent signal-to-noise properties of the order of >10E4. Application of our approach combined with growth of variety of nano materials with controlled organization will be discussed.