Integrated Zinc Oxide Nanotips with Transparent Conductive Film for Photovoltaic Devices

Invention Summary: Researchers at Rutgers University have invented a novel 3-D structure by integrating Zinc Oxide (ZnO) nanotips and ZnO transparent conductive oxide (TCO) film for applications in photovoltaic devices. This novel 3-D structure has multifunctionality with in-situ doping: the ZnO film is heavily doped, acting as the transparent and conductive electrode, while the undoped or less heavily doped single crystalline ZnO nanotips provide n-type semiconductor with nanostructure morphology, acting for anchoring dye and/or polymer molecules. The ZnO nanotips and ZnO TCO film can be grown in the same MOCVD system. The morphology from dense TCO films to nanotips can be achieved by controlling the growth parameters. By doping the ZnO with group III elements, the conductivity of the ZnO nanotips and ZnO TCO films can be tuned and optimized, while still maintaining high transparency in the visible wavelength. The single crystalline ZnO nanotips with preferred c-axis orientation, uniform height and diameter, and high aspect ratio provide large surface area for anchoring dye and/or polymer molecules, and excellent direct conduction pathways for the photo- induced carriers from the point of carrier generation to the collection electrode. The ZnO TCO film has a high transparency in the visible wavelength and low sheet resistance. Market Application: Organic Inorganic Dye Sensitized Solar Cells Advantages: Single material system with low growth temperature compatible with a variety of substrates Fast electron transport in the ZnO nanotips Indium free transparent conducting layer Bandgap control of ZnO layer via Mg doping Light trapping, antireflection and UV light harvesting effects in ZnO nanotips Increased semiconductor area for exciton dissociation in organic solar cells Increased semiconductor area for dye coverage and favorable structure for impregnation of gel electrolytes in dye sensitized solar cells The conductivity of the ZnO nanotips can be tuned from semi-insulating to highly conductive Intellectual Property & Development Status: Patent pending.