Nanoindentation of Chromium Oxide Possessing Superior Hardness among Atomic-Layer-Deposited Oxides

Chromium (III) oxide is a technologically interesting material with attractive chemical, catalytic, magnetic and mechanical properties. It can be produced by different chemical and physical methods, for instance, by metal–organic chemical vapor deposition, thermal decomposition of chromium nitrate Cr(NO3)3 or ammonium dichromate (NH4)2Cr2O7, magnetron sputtering and atomic layer deposition. The latter method was used in the current work to deposit Cr2O3 thin films with thicknesses from 28 to 400 nm at deposition temperatures from 330 to 465 °C. The phase composition, crystallite size, hardness and modulus of elasticity were measured. The deposited Cr2O3 thin films had different structures from X-ray amorphous to crystalline α-Cr2O3 (eskolaite) structures. The averaged hardness of the films on SiO2 glass substrate varied from 12 to 22 GPa and the moduli were in the range of 76–180 GPa, as determined by nanoindentation. Lower values included some influence from a softer deposition substrate. The results indicate that Cr2O3 could be a promising material as a mechanically protective thin film applicable, for instance, in micro-electromechanical devices.

Organic Thin-Film Characteristics Modulated by Deposition Substrate Rotation Speed and the Effect on Organic Light-Emitting Diodes

In this paper, we report on the effects of the substrate thermal evaporation process rotation speed on the electroluminescence (EL) characteristics of organic light-emitting diodes (OLEDs). In general OLED research, rotational and angle tilted deposition are widely used to maintain uniformity. However, there have been few reports on the effects of this deposition method on film characteristics. We analyzed these effects and found that the film density and its refractive index showed remarkable changes as a function of substrate rotational speed during tilted deposition. The EL characteristics of the transport layer of fluorescent OLEDs were also significantly affected. We derived the OLED optimal thickness and refractive index from our calculations.

Simulation of Multilayer Nanosystems Interface Formation Process for Spintronics

Modeling the processes of forming contact regions (interface) of the multilayer niobium-cobalt nanosystem is carried out. The morphology and composition of a multilayer nanosystem interface is investigated. The layer boundaries morphology is shown to depend on the deposition substrate temperature and, largely, is determined by preparing the surface for deposition. The work considers the deposition surface modification by removing its defects. Simulation showed that surface preparation significantly affects the morphology and composition of a multilayer nanosystem interface, depending on the type of deposited atoms and atoms forming the deposition surface.

Riveting the atomically distributed lithiophilic centers in the CNT reinforced interfacial layer: an ultra-thin, light-weight deposition substrate toward superior Li utilization

The dynamically unstable interfacial properties and the low Li utilization degree hinder the practical use of the metallic lithium anodes in the energy-dense battery construction with limited cation source (lean...

Особенности роста гетероструктур нитрида галлия на подложках кремния: управляемая пластическая деформация

Gallium nitride heterostructures were grown on silicon substrates by metalorganic chemical vapour deposition. Substrate plastic deformations that occur during the growth process with the effective compressive stresses accumulation in the film were observed at temperatures of 930oC-975oC. An approach of silicon controlled plastic deformation by high-temperature annealing combined with the in situ SiNx layer growth after heterostructure epitaxy is proposed. This approach would simplify optimization of the gallium nitride heterostructures architecture for various technological tasks.

Influence of Deposition Substrate Temperature on Optical and Electrical Properties of In Situ Boron Doped Amorphous Carbon Film for Solar Cell Applications

The effect of deposition subtrate temperatures by the applied of constant -20 V on electrical and optical properties of in-situ boron-doped amorphous carbon films were determined. From Tauc’s plot, optical band gap (𝐸𝑔) was determined, and 𝐸𝑔 decreased as deposition temperature increased (1.99 eV to 1.90 eV) while the resistivity values were slowly deteriorates from 1.84x106 Ωcm to 4.31x105 Ωcm. The highest and lowest efficiecny of Au/a-C:B/n-Si/Au devices were achieved at 350°C (0.063641 %) and 200°C (0.042691 %), respectively. It can be concluded that by comparing with deposition temperature ranging from 200°C to 350°C under deposition condition used, at 350°C showed the optimum value for solar cell applications.

Study on the preparation and photocatalytic oxidation properties of TiO2/nano-Fe0 photocatalysts

TiO2/nano-Fe0 composite photocatalysts were prepared via a liquid phase reduction deposition method using anatase nano-TiO2 as a deposition substrate.