To use solar irradiation or interior lighting efficiently, we sought a photocatalyst with high reactivity under visible light. Films and powders of TiO 2- x N x have revealed an improvement over titanium dioxide (TiO 2 ) under visible light (wavelength 2 has proven to be indispensable for band-gap narrowing and photocatalytic activity, as assessed by first-principles calculations and x-ray photoemission spectroscopy.

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Visible-Light Photocatalysis in Nitrogen-Doped Titanium Oxides

Titanium Dioxide Nanomaterials: Synthesis, Properties, Modifications, and Applications

[Yang, Hua Gui; Sun, Cheng Hua; Qiao, Shi Zhang; Liu, Gang; Smith, Sean Campbell; Lu, Gao Qing] Univ Queensland, ARC Ctr Excellence Funct Nanomat, Sch Engn, Brisbane, Qld 4072, Australia. [Yang, Hua Gui; Sun, Cheng Hua; Qiao, Shi Zhang; Liu, Gang; Smith, Sean Campbell; Lu, Gao Qing] Univ Queensland, Australian Inst Bioengn & Nanotechnol, Ctr Computat Mol Sci, Brisbane, Qld 4072, Australia. [Zou, Jin] Univ Queensland, Ctr Microscopy & Microanal, Brisbane, Qld 4072, Australia. [Zou, Jin] Univ Queensland, Sch Engn, Brisbane, Qld 4072, Australia. [Liu, Gang; Cheng, Hui Ming] Chinese Acad Sci, Met Res Inst, Shenyang Natl Lab Mat sci, Shenyang 110016, Peoples R China.;Lu, GQ (reprint author), Univ Queensland, ARC Ctr Excellence Funct Nanomat, Sch Engn, Brisbane, Qld 4072, Australia;s.qiao@uq.edu.au maxlu@uq.edu.au

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Anatase TiO(2) single crystals with a large percentage of reactive facets

Fujishima and Honda (1972) demonstrated the potential of titanium dioxide (TiO2) semiconductor materials to split water into hydrogen and oxygen in a photo-electrochemical cell. Their work triggered the development of semiconductor photocatalysis for a wide range of environmental and energy applications. One of the most significant scientific and commercial advances to date has been the development of visible light active (VLA) TiO2 photocatalytic materials. In this review, a background on TiO2 structure, properties and electronic properties in photocatalysis is presented. The development of different strategies to modify TiO2 for the utilization of visible light, including non metal and/or metal doping, dye sensitization and coupling semiconductors are discussed. Emphasis is given to the origin of visible light absorption and the reactive oxygen species generated, deduced by physicochemical and photoelectrochemical methods. Various applications of VLA TiO2, in terms of environmental remediation and in particular water treatment, disinfection and air purification, are illustrated. Comprehensive studies on the photocatalytic degradation of contaminants of emerging concern, including endocrine disrupting compounds, pharmaceuticals, pesticides, cyanotoxins and volatile organic compounds, with VLA TiO2 are discussed and compared to conventional UV-activated TiO2 nanomaterials. Recent advances in bacterial disinfection using VLA TiO2 are also reviewed. Issues concerning test protocols for real visible light activity and photocatalytic efficiencies with different light sources have been highlighted.

/pdf/a-review-on-the-visible-light-active-titanium-dioxide-2qg81s4yao.pdf

A review on the visible light active titanium dioxide photocatalysts for environmental applications

We demonstrate very high efficiency electrophosphorescence in organic light-emitting devices employing a phosphorescent molecule doped into a wide energy gap host. Using bis(2-phenylpyridine)iridium(III) acetylacetonate [(ppy)2Ir(acac)] doped into 3-phenyl-4(1′-naphthyl)-5-phenyl-1,2,4-triazole, a maximum external quantum efficiency of (19.0±1.0)% and luminous power efficiency of (60±5) lm/W are achieved. The calculated internal quantum efficiency of (87±7)% is supported by the observed absence of thermally activated nonradiative loss in the photoluminescent efficiency of (ppy)2Ir(acac). Thus, very high external quantum efficiencies are due to the nearly 100% internal phosphorescence efficiency of (ppy)2Ir(acac) coupled with balanced hole and electron injection, and triplet exciton confinement within the light-emitting layer.

Nearly 100% internal phosphorescence efficiency in an organic light emitting device

PURPOSE: To protect a surface protective film which covers the thin film resistance element of a semiconductor device from thermal damages due to trimming or a current heating treatment. CONSTITUTION: A semiconductor device is composed of a substrate 1, a thin film resistance element 3 which is formed on the substrate 1 directly or with an insulating film 2 therebetween and which can be trimmed by laser application or current heating and a surface protective film 6 which is formed on the thin film resistance element 3 directly or with an insulating film therebetween. The surface protective film 6 is composed of at least aluminum 5 and nitrogen. In the semiconductor device like this, the damages to the surface protective film 6 due to thermal stress can be suppressed and the relability and durability of the semiconductor device can be improved.

Semiconductor device having thin film resistance element

Interfacial structures between Ta2O5–SnO2 (Ta–Sn–O) films and indium tin oxide (ITO) electrodes were studied using transmission electron microscopy (TEM) and secondary ion mass spectroscopy (SIMS). It was found that indium atoms diffused into the Ta2O5 film by annealing (at 923 K for 30 min in N2 atmosphere), while diffusion was not observed at the Ta–Sn–O/ITO interface. The thermal stability of the interfaces of Ta2O5/ITO and Ta–Sn–O/ITO can be explained in terms of the difference of the diffusion behavior at the interface, which affect the superior electrical properties of the Ta–Sn–O/ITO structures.

https://iopscience.iop.org/article/10.1143/JJAP.36.L1699/pdf

Interfacial Stability Between Ta-Sn-O Films and Indium Tin Oxide Electrodes

Structures of Y-Ba-Cu-O sputter-deposited films were investigated by Scanning Electron Microscopy (SEM) and Auger Electron Spectroscopy (AES). After heat treatment, the films showed different morphology for different substrates, i.e., A12O3 and MgO, and for different thicknesses of 0.1 μm and 1.2 μm. Only for YBaCuO(P.1μm)/MgO, highly oriented crystal growth is seen, and for other systems, inhomogeneous crystal growths are seen. An interface roughning caused by preferential interdiffusion of Ba into an A12O3 substrate was observed. A surface enrichment of Cu is found for the thick films. These differences in morphology are considered to be due to the differences in the diffusion processes.

Yasunori Taga

Papers

Semiconductor device having thin film resistance element

Interfacial Stability Between Ta-Sn-O Films and Indium Tin Oxide Electrodes

Observations of Y-Ba-Cu-O Films by Scanning Electron Microscopy and Auger Electron Spectroscopy

Effect of water adsorption on Ti film initial growth on SiO2 surface

Morphological Stability of TiO_2 Thin Films With Isolated Columns : Surfaces, Interfaces, and Films