Crystal Structure, Cation Occupation, and Phase Transitions in Ba(LiNa)NbO Tetragonal Tungsten Bronzes.

The chemical flexibility of the tetragonal tungsten bronze (TTB) structure offers a large potential for compositional engineering. Cation size and vacancy concentration are known to affect its structure, cation disorder, and functional properties. However, the compositional complexity also makes the TTB structure challenging to understand.

The effect of cation size on structure and properties of Ba-based tetragonal tungsten bronzes BaMNbO (M = Na, K or Rb) and BaMNbTiO (M = Ca or Sr).

The second largest family of oxide ferroelectrics, after perovskites, are the tetragonal tungsten bronzes (TTB) with the general formula A2A1CB1B2O. Cation disorder in TTBs is known to occur if the size difference between cations is small, but the impact of cation disorder on structure and properties has not yet been extensively addressed. In this study we investigate the effect of the size of the M cation, including cation disorder, on the crystal structure and dielectric properties in the two series BaMNbO (BMN, A = Na, K and Rb) and BaMNbTiO (BMNT, M = Ca, Sr).

Correction: Investigation of factors affecting the stability of compounds formed by isovalent substitution in layered oxychalcogenides, leading to identification of BaScOCuSe, BaYOCuSe, BaScOAgSe and BaInOAgSe.

[This corrects the article DOI: 10.1039/D1TC05051F.].

Computational Prediction and Experimental Realization of Earth-Abundant Transparent Conducting Oxide Ga-Doped ZnSbO.

Transparent conducting oxides have become ubiquitous in modern optoelectronics. However, the number of oxides that are transparent to visible light and have the metallic-like conductivity necessary for applications is limited to a handful of systems that have been known for the past 40 years. In this work, we use hybrid density functional theory and defect chemistry analysis to demonstrate that tri-rutile zinc antimonate, ZnSbO, is an ideal transparent conducting oxide and to identify gallium as the optimal dopant to yield high conductivity and transparency.

Investigation of factors affecting the stability of compounds formed by isovalent substitution in layered oxychalcogenides, leading to identification of BaScOCuSe, BaYOCuS, BaScOAgSe and BaInOAgSe.

Four novel compositions containing chalcogenide layers, adopting the BaMOM'Ch layered structure have been identified: BaScOCuSe, BaYOCuS, BaScOAgSe and BaInOAgSe. A comprehensive comparison of experimental and computational results providing the crystallographic and electronic structure of the compounds under investigation has been conducted. Materials were synthesised at 800 °C under vacuum using a conventional ceramic synthesis route with combination of binary oxide and chalcogenide precursors.

Computationally Driven Discovery of Layered Quinary Oxychalcogenides: Potential -Type Transparent Conductors?

-type transparent conductors (TCs) are key materials in the modern optoelectronics industry. Despite years of research, the development of a high-performance -type TC has lagged far behind that of its -type counterparts, delaying the advent of "transparent electronics"-based p-n junctions. Here, we propose the layered oxysulfide [CuS][SrScO] as a structural motif for discovering -type TCs.

Resonant Ta Doping for Enhanced Mobility in Transparent Conducting SnO.

Transparent conducting oxides (TCOs) are ubiquitous in modern consumer electronics. SnO is an earth abundant, cheaper alternative to InO as a TCO. However, its performance in terms of mobilities and conductivities lags behind that of InO.

Enhanced Photocatalytic and Antibacterial Ability of Cu-Doped Anatase TiO Thin Films: Theory and Experiment.

Multifunctional thin films which can display both photocatalytic and antibacterial activity are of great interest industrially. Here, for the first time, we have used aerosol-assisted chemical vapor deposition to deposit highly photoactive thin films of Cu-doped anatase TiO on glass substrates. The films displayed much enhanced photocatalytic activity relative to pure anatase and showed excellent antibacterial (vs and ) ability.

Origin of High-Efficiency Photoelectrochemical Water Splitting on Hematite/Functional Nanohybrid Metal Oxide Overlayer Photoanode after a Low Temperature Inert Gas Annealing Treatment.

A simplistic and low-cost method that dramatically improves the performance of solution-grown hematite photoanodes for solar-driven water splitting through incorporation of nanohybrid metal oxide overlayers was developed. By heating the α-FeO/SnO-TiO electrode in an inert atmosphere, such as argon or nitrogen, the photocurrent increased to over 2 mA/cm at 1.23 V versus a reversible hydrogen electrode, which is 10 times higher than that of pure hematite under 1 sun (100 mW/cm, AM 1.

Dispelling the Myth of Passivated Codoping in TiO.

Modification of TiO to increase its visible light activity and promote higher performance photocatalytic ability has become a key research goal for materials scientists in the past 2 decades. One of the most popular approaches proposed this as "passivated codoping", whereby an equal number of donor and acceptor dopants are introduced into the lattice, producing a charge neutral system with a reduced band gap. Using the archetypal codoping pairs of [Nb + N]- and [Ta + N]-doped anatase, we demonstrate using hybrid density functional theory that passivated codoping is not achievable in TiO.

Phosphorus doped SnO thin films for transparent conducting oxide applications: synthesis, optoelectronic properties and computational models.

Phosphorus doped tin(iv) oxide (P:SnO) films have been synthesised by an aerosol assisted chemical vapour deposition route. Triethyl phosphate was used as the phosphorus dopant source. The phosphorus concentration in solution was found to be key to electrical properties, with concentrations between 0.

A novel laboratory-based hard X-ray photoelectron spectroscopy system.

Hard X-ray photoelectron spectroscopy (HAXPES) has seen continuous development since the first experiments in the 1970s. HAXPES systems are predominantly located at synchrotron sources due to low photoionization cross sections necessitating high X-ray intensities, which limits the technique's availability to a wide range of users and potential applications. Here, a new laboratory-based instrument capable of delivering monochromated X-rays with an energy of 9.

Chemical Vapor Deposition Synthesis and Optical Properties of NbO Thin Films with Hybrid Functional Theoretical Insight into the Band Structure and Band Gaps.

NbO is an important material able to exist in many polymorphs with unique optical properties and morphologies that are dependent on the synthetic route. Here we report a novel ambient-pressure chemical vapor deposition route to NbO via aerosol-assisted chemical vapor deposition. The amorphous as-deposited films were annealed in air to obtain the the three most stable crystal structures: orthorhombic, tetragonal, and monoclinic.

A single-source precursor approach to solution processed indium arsenide thin films.

This paper reports the synthesis of the novel single-source precursor, [{(MeInAs Bu)}(MeInAs( Bu)H)] and the subsequent first report of aerosol-assisted chemical vapour deposition of InAs thin films. Owing to the use of the single-source precursor, highly crystalline and stoichiometric films were grown at a relatively low deposition temperature of 450 °C. Core level XPS depth profiling studies showed some partial oxidation of the film surface, however this was self-limiting and disappeared on etch profiles.