The semiconductor ZnO has gained substantial interest in the research community in part because of its large exciton binding energy (60meV) which could lead to lasing action based on exciton recombination even above room temperature. Even though research focusing on ZnO goes back many decades, the renewed interest is fueled by availability of high-quality substrates and reports of p-type conduction and ferromagnetic behavior when doped with transitions metals, both of which remain controversial. It is this renewed interest in ZnO which forms the basis of this review. As mentioned already, ZnO is not new to the semiconductor field, with studies of its lattice parameter dating back to 1935 by Bunn [Proc. Phys. Soc. London 47, 836 (1935)], studies of its vibrational properties with Raman scattering in 1966 by Damen et al. [Phys. Rev. 142, 570 (1966)], detailed optical studies in 1954 by Mollwo [Z. Angew. Phys. 6, 257 (1954)], and its growth by chemical-vapor transport in 1970 by Galli and Coker [Appl. Phys. ...

/pdf/a-comprehensive-review-of-zno-materials-and-devices-21a3zjadem.pdf

A comprehensive review of zno materials and devices

This critical review shows the basis of photocatalytic water splitting and experimental points, and surveys heterogeneous photocatalyst materials for water splitting into H2 and O2, and H2 or O2 evolution from an aqueous solution containing a sacrificial reagent Many oxides consisting of metal cations with d0 and d10 configurations, metal (oxy)sulfide and metal (oxy)nitride photocatalysts have been reported, especially during the latest decade The fruitful photocatalyst library gives important information on factors affecting photocatalytic performances and design of new materials Photocatalytic water splitting and H2 evolution using abundant compounds as electron donors are expected to contribute to construction of a clean and simple system for solar hydrogen production, and a solution of global energy and environmental issues in the future (361 references)

Heterogeneous photocatalyst materials for water splitting

Transparent electronic devices formed on flexible substrates are expected to meet emerging technological demands where silicon-based electronics cannot provide a solution. Examples of active flexible applications include paper displays and wearable computers1. So far, mainly flexible devices based on hydrogenated amorphous silicon (a-Si:H)2,3,4,5 and organic semiconductors2,6,7,8,9,10 have been investigated. However, the performance of these devices has been insufficient for use as transistors in practical computers and current-driven organic light-emitting diode displays. Fabricating high-performance devices is challenging, owing to a trade-off between processing temperature and device performance. Here, we propose to solve this problem by using a novel semiconducting material—namely, a transparent amorphous oxide semiconductor from the In-Ga-Zn-O system (a-IGZO)—for the active channel in transparent thin-film transistors (TTFTs). The a-IGZO is deposited on polyethylene terephthalate at room temperature and exhibits Hall effect mobilities exceeding 10 cm2 V-1 s-1, which is an order of magnitude larger than for hydrogenated amorphous silicon. TTFTs fabricated on polyethylene terephthalate sheets exhibit saturation mobilities of 6–9 cm2 V-1 s-1, and device characteristics are stable during repetitive bending of the TTFT sheet.

Room-temperature fabrication of transparent flexible thin-film transistors using amorphous oxide semiconductors

2.3. Evaluation of Photocatalytic Water Splitting 6507 2.3.1. Photocatalytic Activity 6507 2.3.2. Photocatalytic Stability 6507 3. UV-Active Photocatalysts for Water Splitting 6507 3.1. d0 Metal Oxide Photocatalyts 6507 3.1.1. Ti-, Zr-Based Oxides 6507 3.1.2. Nb-, Ta-Based Oxides 6514 3.1.3. W-, Mo-Based Oxides 6517 3.1.4. Other d0 Metal Oxides 6518 3.2. d10 Metal Oxide Photocatalyts 6518 3.3. f0 Metal Oxide Photocatalysts 6518 3.4. Nonoxide Photocatalysts 6518 4. Approaches to Modifying the Electronic Band Structure for Visible-Light Harvesting 6519

Semiconductor-based Photocatalytic Hydrogen Generation

We report the fabrication of transparent field-effect transistors using a single-crystalline thin-film transparent oxide semiconductor, InGaO 3 (ZnO) 5 , as an electron channel and amorphous hafnium oxide as a gate insulator. The device exhibits an on-to-off current ratio of ∼10 6 and a field-effect mobility of ∼80 square centimeters per volt per second at room temperature, with operation insensitive to visible light irradiation. The result provides a step toward the realization of transparent electronics for next-generation optoelectronics.

http://science.sciencemag.org/content/sci/300/5623/1269.full.pdf

Thin-Film Transistor Fabricated in Single-Crystalline Transparent Oxide Semiconductor

PROBLEM TO BE SOLVED: To provide a substrate with a thin film having a (Zn 1-x Cu x )Se thin film on a substrate, more particularly an organic polymer substrate. SOLUTION: The substrate and the substrate with the thin film characterized by including the (Zn 1-x Cu x )Se thin film (where 0≤x≤0.2) prepared in at least a part on the front face of the substrate are provided. The method for manufacturing the substrate with the thin film comprises heating ZnSe within a vacuum vapor deposition vessel arranged with the substrate, and heating CuSe and/or Cu 2 Se to form the (Zn 1-x Cu x )Se thin film (where 0≤x≤0.2) on the front face of the substrate. COPYRIGHT: (C)2009,JPO&INPIT

SUBSTRATES WITH ZnCuSe THIN FILM, AND ITS MANUFACTURING METHOD

The title compound, indium iron titanium oxide, is closely related to InFeO 3 , having a hexagonal structure which consists of alternating layers of InO 6 octahedra and FeO 5 trigonal bipyramids. According to substitution of Ti 4+ for Fe 3+ , excess O atoms are introduced into the Fe-O trigonal lattice plane of InFeO 3 . The inplane arrangement of O atoms can be described as partial occupation on a honeycomb lattice, although large displacement parameters indicate local shifts of 0 atoms due to repulsive interactions between them.

Orthorhombic InFe0.33Ti0.67O3.33.

PURPOSE:To make it possible to form an oxide superconductive material having a small transition temperature width and excellent superconductive characteristics by forming a layer, which is composed of a reaction product of a solution including specific two kinds of elements as components and a precipitation formative agent, on the metallic copper surface and then conducting a heat treatment. CONSTITUTION:A layer composed of a reaction product of a solution including M1 and M2 as components and a precipitation formative agent is formed on the metallic copper surface, and then a heat treatment is conducted. In this case, M1 is, for instance, one kind of alkaline earth metallic elements such as Ca, Ba, and Sr, and M2 is, for instance, one kind of rare earth elements such as Sc, Y, La, Ce, Pr, Nd, and Pm, and the atomic ratio between M1 and M2 is preferably 2:1 from the viewpoint of superconductiveness. A solution including M1 and M2 as components is a water system solution prepared using the reaction between inorganic salt or oxygen and metal, and an organic solvent system solution prepared using an organic metallic compound such as alkoxide etc. This enables an oxide superconductive layer having a small superconductivity transition temperature width and excellent superconductive characteristics to be formed on the metallic copper surface.

Manufacture of oxide superconductive material

Indium-tin-oxide films were grown hetero-epitaxially on YSZ surface at a substrate temperature of 900 °C, and their surface microstructures were observed by using atomic force microscopy. ITO films grown on (111) surface of YSZ exhibited very high crystal quality; full width at half maximum of out-of-plane rocking curve was 54 second. The ITO was grown spirally, with flat terraces and steps corresponding to (222) plane spacing of 0.29 nm. Oxygen pressure during film growth is another key factor to obtain atomically flat surfaced ITO thin film.

Transparent Conducting Indium-Tin-Oxide Thin Film with Extremely Flatted Surface

PURPOSE: To provide an IR reflecting film almost perfectly transmitting visible light over a region to short wavelength and having high IR reflectance CONSTITUTION: This IR reflecting film is represented by the general formula, M (1)XM (2)y Inz O(x+3y/2+3z/2)-d [where M (1) is at least one of Mg and Zn, M (2) is at least one of Al and Ga, the ratio of x:y is (02-18):1, the ratio of z:y is (04-14):1 and oxygen deficiency (d) is 3×10 -1×10 time as much as (x+3y/2+3z/2)] Other element may be substd for part of at least one among M (1), M (2) and In in the above-mentioned formula [where the lower limit of (d) is o] The valence of an element substd for M (1) is >=2 and that of each of elements substd for M (2) and In is >=3 This IR reflecting film may be a film obtd by implanting cations into a film of an oxide represented by the above-mentioned formula [where the lower limit of (d) is 0]

Masahiro Orita

Papers

SUBSTRATES WITH ZnCuSe THIN FILM, AND ITS MANUFACTURING METHOD

Orthorhombic InFe0.33Ti0.67O3.33.

Manufacture of oxide superconductive material

Transparent Conducting Indium-Tin-Oxide Thin Film with Extremely Flatted Surface

Infrared-ray reflecting film