United Kingdom
United Kingdom

Time filter

Source Type

Dabirian A.,Ecole Polytechnique Federale de Lausanne | Kuzminykh Y.,Ecole Polytechnique Federale de Lausanne | Afra B.,Ecole Polytechnique Federale de Lausanne | Harada S.,Ecole Polytechnique Federale de Lausanne | And 7 more authors.
Electrochemical and Solid-State Letters | Year: 2010

Combinatorial high vacuum chemical vapor deposition (HV-CVD) of mixed HfO2 - Nb2 O5 thin films has been demonstrated to yield amorphous layers at substrate temperatures where individually deposited pure HfO2 and Nb2 O5 films are polycrystalline. Spectroscopic ellipsometry of the films shows that adding HfO2 to Nb2 O5 improves the transparency of the films while still maintaining a high refractive index. Atomic force microscopy measurements show that the root-mean-square surface roughness of the films is about 1.2 nm. © 2010 The Electrochemical Society.


Dabirian A.,Ecole Polytechnique Federale de Lausanne | Dabirian A.,Technical University of Delft | Harada S.,Ecole Polytechnique Federale de Lausanne | Kuzminykh Y.,Ecole Polytechnique Federale de Lausanne | And 9 more authors.
Journal of the Electrochemical Society | Year: 2011

A combinatorial chemical beam epitaxy technique was used to optimize deposition of {001} lithium niobate thin films on {001} sapphire substrates. Lithium tert-butoxide [Li (O But)] and niobium tetra-ethoxy di-methyl-amino-ethoxide [Nb(OEt)4(dmae)] were used as precursors. The highest quality films obtained exhibited rocking curve full-width at half-maximum values of about 0.03° and lithium contents { [Li]/[((Li)) + (Nb)] } larger than 48 (mol %) estimated by Raman spectroscopy. High-resolution transmission electron microscopy observations revealed that the lithium niobate film consists of a buffer layer (thickness <8 nm) with a high density of defects above which the epitaxial lithium niobate film was obtained. © 2010 The Electrochemical Society.


Sarkar A.,TU Eindhoven | Potts S.E.,TU Eindhoven | Rushworth S.A.,SAFC Hitech Ltd. | Roozeboom F.,TU Eindhoven | And 2 more authors.
ECS Transactions | Year: 2010

Titanium oxide thin films of both amorphous and anatase morphologies have been deposited using remote plasma ALD over a wide temperature range (100-350°C), using a novel heteroleptic alkylamido precursor Ti(Cp Me)(NMe2)3. A high growth per cycle (GPC) of 0.07-0.08 nm (which is about 50 % higher than the GPC obtained with most other organometallic precursors) without any nucleation delay was observed. Rutherford backscattering (RBS) and X-ray photoelectron spectroscopy (XPS) studies on the deposited films revealed their stoichiometry and compositional purity: samples deposited at 100-350°C had [O]/[Ti] ratios of ∼2.0±0.1. Samples deposited at 200°C and above had C, H and N concentrations of less than 0.6, 2 and 2.3 at.%, respectively. Atomic force microscopy (AFM) and X-ray diffraction (XRD) studies revealed that films deposited at 300°C and above had a significant crystalline (anatase) component, while films deposited at 100 and 200°C were amorphous. ©The Electrochemical Society.


Dabirian A.,Ecole Polytechnique Federale de Lausanne | Kuzminykh Y.,Ecole Polytechnique Federale de Lausanne | Kuzminykh Y.,Empa - Swiss Federal Laboratories for Materials Science and Technology | Sandu S.C.,Ecole Polytechnique Federale de Lausanne | And 8 more authors.
Crystal Growth and Design | Year: 2011

Combinatorial high-vacuum chemical vapor deposition (HV-CVD) was used to identify the conditions required to obtain hafnium-doped lithium niobate thin films on sapphire {001} substrates. Niobium tetraethoxydimethylaminoethoxide (Nb(OEt)4(dmae)), lithium tert-butoxide (Li(OBut)), and hafnium tert-butoxide (Hf(OBut)4) were used as precursors. X-ray diffraction (XRD) and transmission electron microscopy (TEM) indicated that a single phase of textured {001} Hf-doped lithium niobate film was obtained under certain precursor flux conditions. The lithium content ([Li]/([Li] + [Nb])) of the textured film was estimated using Raman spectroscopy to be about 49 mol %. The presence of hafnium inside the films was confirmed by X-ray photoelectron spectroscopy (XPS) measurements, and the hafnium content of the textured film ([Hf]/([Hf] + [Nb])) was estimated to be about 3 mol %. XPS data confirmed that Hf and Nb, respectively, are in the +4 and +5 oxidation states inside the film. The film consists of nearly parallel {001} hafnium-doped lithium niobate columns with different in-plane orientations. © 2010 American Chemical Society.


Potts S.E.,University College London | Potts S.E.,TU Eindhoven | Carmalt C.J.,University College London | Blackman C.S.,University College London | And 5 more authors.
Inorganica Chimica Acta | Year: 2010

Low pressure chemical vapour deposition (LPCVD) of [ZrCp2(NMe2)2] (1), [ZrCp2(η2-MeNCH2CH2NMe)] (2), [ZrCp′2(NMe2)2] (3) and [ZrCp′2(NEt2)2] (4) (Cp = η5-cyclopentadienyl, Cp′ = η5-monomethylcyclopentadienyl), onto glass substrates at 600 °C, afforded highly reflective and adhesive films of zirconium carbide and amorphous carbon. Powder XRD indicated that the films were largely amorphous, although small, broad peaks accounting for ZrC and ZrO2 were present, suggesting that the remaining carbon was due to amorphous deposits from the cyclopentadienyl ligands. SEM images showed an island-growth mechanism with distinct crevices between the concentric nodules. Plasma-enhanced atomic layer deposition (PEALD) of compounds 1 and 2 showed that the precursors were not sufficiently stable or volatile to give a good rate of film growth. © 2009 Elsevier B.V. All rights reserved.


Dabirian A.,Ecole Polytechnique Federale de Lausanne | Dabirian A.,Technical University of Delft | Kuzminykh Y.,Empa - Swiss Federal Laboratories for Materials Science and Technology | Wagner E.,3D Oxide | And 3 more authors.
ChemPhysChem | Year: 2011

Laser-assisted deposition: The discovery of chemical vapor deposition (CVD) conditions under which the growth rate is a decreasing function of the precursor flux has the potential to boost the resolution of laser-assisted CVD processes whereas flux- and desorption-limited conditions appear to be the ideal environment for spatially addressable combinatorial experiments (see picture). Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Patent
Safc Hitech Inc. | Date: 2014-10-24

Metal complexes containing one or more amidoimine ligands, methods of making such metal complexes, and methods of using such metal complexes to prepare metal-containing films are provided.


Grant
Agency: European Commission | Branch: FP7 | Program: CP-FP | Phase: NMP.2013.4.0-2 | Award Amount: 5.13M | Year: 2013

The ArtESun project combines the multidisciplinary and complementary competences of top-level European research groups and industries in order to make significant steps towards high-efficiency >15%, stable and cost efficient OPV technology. For this purpose, the project objectives are set to make break-through advances in the state of the art in terms of (i) the development of innovative high efficient OPV materials which can be used to demonstrate the cost-effective non-vacuum production of large area arbitrary size and shape OPV modules (ii) understanding of the long term stable operation and the degradation mechanisms at the material and OPV device level (iii) the development of roll-to-roll (R2R) additive non-vacuum coating and printing techniques emphasizing efficient materials usage and cost efficient R2R processing and (iv) demonstration of high performance arbitrary size and shape OPV systems in environments relevant to its expected future applications.


Grant
Agency: European Commission | Branch: FP7 | Program: CP-FP | Phase: NMP-2009-1.2-1 | Award Amount: 3.17M | Year: 2010

Renewable energy production is a key driver for innovation in the material domain. Researchers and industries look to reduce the energy cost and to increase the efficiency of PV solar cells. Nanotechnologies and nanomaterials show broad opportunities. Indeed, at the nanoscale level, energy band gaps depend on nanomaterial architectures (nanoparticles size, bulk dispersion, interfaces with embedding matrix). Silicon nanocrystals allow the design of highly efficiency architectures, like multijunction solar cells or low-cost, optimised, thin film solar cells. The usual elaboration technique is based on the deposition of either multilayer or nanocomposite material in which excess silicon is aggregated into nanoparticles through high temperature annealing. No control of nanoparticle size and bulk dispersion is possible. Moreover, only limited surrounding materials could be considered (silicon containing). This prevents any knowledge-based tuning of the material properties. The main objective of SNAPSUN project is to develop a nanomaterial with reliable and tailored characteristics. To overcome limitations described above, fully tailored silicon nanoparticles will be optimised, in terms of size (3nm) and size dispersion (>10%;0.3nm). The SNAPSUN innovation is the incorporation of these silicon nanoparticles in a wide band gap material, such as silicon carbide or Transparent Conductive Oxides (TCO). This architecture will allow band gap engineering through accurate structure control, together with exceptional electrical characteristics (resistivity, carrier lifetime, etc.) in order to produce high conversion efficiencies above 25 %. Control of material structure will arise from the development of very promising processes allowing the separation of nanoparticle generation and embedding matrix codeposition. Vacuum and wet technologies will be used to target low-cost solar cells with a target production cost below 0.5 /Wpeak.


PubMed | University of Bath and SAFC Hitech Ltd
Type: Journal Article | Journal: Dalton transactions (Cambridge, England : 2003) | Year: 2016

The stannous alkoxides [Sn(OR)

Loading SAFC Hitech Ltd collaborators
Loading SAFC Hitech Ltd collaborators