Transparent antireflective layers of oxide nanowires grown from thin films by pressurized contact interdiffusion processes

Oxide phase nanowires are important for applications ranging from optoelectronics to water splitting, but prove difficult to grow in high density with good crystalline quality and phase purity. Heterogeneous catalysts are typically required to nucleate growth. This work demonstrates that dispersions of oxide nanowires can be formed directly from solution processed oxide thin films. We also examine the effect of changes in applied pressure between a solution processed vanadium oxide thin film and a surface-contacted glass coupon on the catalyst-free formation of interconnected sodium vanadate nanowire structures by interdiffusion. Under different applied pressures, meshes of high quality crystalline oxide nanowires formed on the surface, and we examine the nature of phase conversion and nanostructure growth including larger shards composed of multiple conjoined nanowires are also examined. The optical properties of the oxides NWs formed by interdiffusion from oxide thin films show promising properties for application as antireflective coatings across a broadband spectral range. This interdiffusion technique is effective for high quality oxide nanowire growth without catalysts directly from insulating or conducting thin films by direct contact with a source of diffusing species

Photoreduction of metal nanostructures on periodically proton exchanged MgO-doped lithium niobate crystals

Local reactivity on periodically proton exchanged lithium niobate (PPE:LN) surfaces is a promising route for the fabrication of regularly spaced nanostructures. Here, using MgO-doped PPE:LN templates, we investigate the influence of the doping on the nanostructure formation as a function of the proton exchange (PE) depth. The deposition is found to occur preferentially along the boundary between MgO-doped LN and the PE region when the PE depth is at least 1.73 μm, however, for shallower depths, deposition occurs across the entire PE region. The results are found to be consistent with an increased photoconductivity of the MgO-doped LN.Science Foundation IrelandDGPPNANOREMEDIESProgramme for Research in Third Level Institutions (PRTLI) Cycle 5European Regional Development FundSwedish Research CouncilUCD ResearchAuthor has checked copyrightDOI link not active A

Direct shape control of photoreduced nanostructures on proton exchanged ferroelectric templates

Photoreduction on a periodically proton exchanged ferroelectric crystal leads to the formation of periodic metallic nanostructures on the surface. By varying the depth of the proton exchange (PE) from 0.59 to 3.10 µm in congruent lithium niobate crystals, the width of the lateral diffusion region formed by protons diffusing under the mask layer, can be controlled. The resulting deposition occurs in the PE region with the shallowest PE depth, and preferentially in the lateral diffusion region for greater PE depths. PE depth-control provides a route for the fabrication of complex metallic nanostructures with controlled dimensions on chemically patterned ferroelectric templates.Science Foundation IrelandThis publication has emanated from research conducted with the financial support of the DGPP and NANOREMEDIES, which are funded under the Programme for Research in Third Level Institutions (PRTLI) Cycle 5 and co-funded by the European Regional Development Fund. We also acknowledge support from the Swedish Research Council (VR 622-2010-526 and 621-2011-4040). The AFM used for this work was funded by Science Foundation Ireland (SFI07/IN1/B931).Author has checked copyrightTS 27.03.1

Photoreduction of metal nanostructures on periodically proton exchanged MgO-doped lithium niobate crystals

Local reactivity on periodically proton exchanged lithium niobate (PPE:LN) surfaces is a promising route for the fabrication of regularly spaced nanostructures. Here, using MgO-doped PPE:LN templates, we investigate the influence of the doping on the nanostructure formation as a function of the proton exchange (PE) depth. The deposition is found to occur preferentially along the boundary between MgO-doped LN and the PE region when the PE depth is at least 1.73 μm, however, for shallower depths, deposition occurs across the entire PE region. The results are found to be consistent with an increased photoconductivity of the MgO-doped LN.Science Foundation IrelandDGPPNANOREMEDIESProgramme for Research in Third Level Institutions (PRTLI) Cycle 5European Regional Development FundSwedish Research CouncilUCD ResearchAuthor has checked copyrightDOI link not active A