Daniel Araújo Gay
@uca.es
Science Faculty
Cadiz University
Prof. Daniel ARAUJO is Dr. in Science and physicist of the EPFL Switzerland, (PhD in 1992). Nowadays, he is Full Professor at University of Cadiz (Spain, since 2010) in the Department of Material Science and Engineering and at the Lyon Institute of Technology (INSA-Lyon, France, since 2004, presently in détachement). His activity is actually focused on two different topics: (i) aerospace materials in collaboration with Airbus and FIDAMC (Foundation for Research, Development and Application of Composite Materials), (ii) Homoepitaxial diamond for power devices. In the latter, he is responsible of H2020 and national projects. He has been supervisor of 11 doctoral theses and is author of more than 140 JCR publications and 16 invited/plenary conferences.
EDUCATION
1-. Universidad de Cádiz: Cadiz, Andalucía, ES
1993-01-01 hasta 1994-12-01 | (Ciencias de los Materiales Ingeniería Metalúrgica y Química Inorgánica)
2-. IBM Zurich Research Laboratory: Zurich, Zürich, CH
1992-08-01 hasta 1993-02-01Education
3-. École Polytechnique Fédérale de Lausanne: Lausanne, VD, CH
1988-10-01 hasta 1992-09-30 | (Instituto de micro-optoelectrónica (IMO)
4-. Ecoles du canton de Vaud: Lausanne, Cantón de Vaud, CH
1982-01-01 hasta 1988-01-01 |
5-. École Polytechnique Fédérale de Lausanne: Lausanne, VD, CH
1982-10-01 hasta 1987-06-01 |
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Scopus Publications
J. Millán-Barba, A. Taylor, H. Bakkali, R. Alcantara, F. Lloret, R. Guzmán de Villoria, M. Dominguez, V. Mortet, M. Gutiérrez, and D. Araújo
Elsevier BV
B. Soto, M. Couret, J. Cañas, A. Castelan, N. Rouger, D. Araujo, M.P. Villar, and J. Pernot
Elsevier BV
J. Millán-Barba, H. Bakkali, F. Lloret, M. Gutiérrez, R. Guzmán de Villoria, M. Domínguez, K. Haenen, and D. Araujo
Elsevier BV
F. Lloret, B. Soto, R. Rouzbahani, M. Gutiérrez, K. Haenen, and D. Araujo
Elsevier BV
Patrick S. Salter, M. Pilar Villar, Fernando Lloret, Daniel F. Reyes, Marta Krueger, Calum S. Henderson, Daniel Araujo, and Richard B. Jackman
American Chemical Society (ACS)
Diamond, as the densest allotrope of carbon, displays a range of exemplary material properties that are attractive from a device perspective. Despite diamond displaying high carbon–carbon bond strength, ultrashort (femtosecond) pulse laser radiation can provide sufficient energy for highly localized internal breakdown of the diamond lattice. The less-dense carbon structures generated on lattice breakdown are subject to significant pressure from the surrounding diamond matrix, leading to highly unusual formation conditions. By tailoring the laser dose delivered to the diamond, it is shown that it is possible to create continuously modified internal tracks with varying electrical conduction properties. In addition to the widely reported conducting tracks, conditions leading to semiconducting and insulating written tracks have been identified. High-resolution transmission electron microscopy (HRTEM) is used to visualize the structural transformations taking place and provide insight into the different conduction regimes. The HRTEM reveals a highly diverse range of nanocarbon structures are generated by the laser irradiation, including many signatures for different so-called diaphite complexes, which have been seen in meteorite samples and seem to mediate the laser-induced breakdown of the diamond. This work offers insight into possible formation methods for the diamond and related nanocarbon phases found in meteorites.
Yamina Benamra, Laurent Auvray, Jérôme Andrieux, François Cauwet, Maria-Paz Alegre, Fernando Lloret, Daniel Araujo, Marina Gutierrez, and Gabriel Ferro
Trans Tech Publications, Ltd.
In this work, the successful heteroepitaxial growth of boron carbide (BxC) on 4HSiC(0001) 4° off substrate using chemical vapor deposition (CVD) is reported. Towards this end, a two-step procedure was developed, involving the 4H-SiC substrate boridation under BCl3 precursor at 1200°C, followed by conventional CVD under BCl3 + C3H8 at 1600°C. Such a procedure allowed obtaining reproducibly monocrystalline (0001) oriented films of BxC with a step flow morphology at a growth rate of 1.9 μm/h. Without the boridation step, the layers are systematically polycrystalline. The study of the epitaxial growth mechanism shows that a monocrystalline BxC layer is formed after boridation but covered with a B-and Si-containing amorphous layer. Upon heating up to 1600°C, under pure H2 atmosphere, the amorphous layer was converted into epitaxial BxC and transient surface SiBx and Si crystallites. These crystallites disappear upon CVD growth.
C. Masante, J. de Vecchy, F. Mazen, F. Milesi, L. Di Cioccio, J. Pernot, F. Lloret, D. Araujo, J.C. Pinero, N. Rochat,et al.
Elsevier BV
B. Soto, J. Cañas, M.P. Villar, D. Araujo, and J. Pernot
Elsevier BV
Daniel Araujo, Mariko Suzuki, Fernando Lloret, Gonzalo Alba, and Pilar Villar
MDPI AG
Progress in power electronic devices is currently accepted through the use of wide bandgap materials (WBG). Among them, diamond is the material with the most promising characteristics in terms of breakdown voltage, on-resistance, thermal conductance, or carrier mobility. However, it is also the one with the greatest difficulties in carrying out the device technology as a result of its very high mechanical hardness and smaller size of substrates. As a result, diamond is still not considered a reference material for power electronic devices despite its superior Baliga’s figure of merit with respect to other WBG materials. This review paper will give a brief overview of some scientific and technological aspects related to the current state of the main diamond technology aspects. It will report the recent key issues related to crystal growth, characterization techniques, and, in particular, the importance of surface states aspects, fabrication processes, and device fabrication. Finally, the advantages and disadvantages of diamond devices with respect to other WBG materials are also discussed.
Josué Millán-Barba, Marina Gutiérrez, Fernando Lloret, Roberto Guzmán de Villoria, Rodrigo Alcántara, Ken Haenen, and Daniel Araujo
Wiley
D. Araujo, F. Lloret, G. Alba, M. P. Alegre, and M. P. Villar
AIP Publishing
Rozita Rouzbahani, Shannon S. Nicley, Danny E.P. Vanpoucke, Fernando Lloret, Paulius Pobedinskas, Daniel Araujo, and Ken Haenen
Elsevier BV
G. Alba, D. Leinen, M.P. Villar, R. Alcántara, J.C. Piñero, A. Fiori, T. Teraji, and D. Araujo
Elsevier BV
Abstract Tungsten carbide (WC) contacts deposited on oxygenated diamond surface have shown great importance in the field of diamond-based Schottky diodes. In previous works, high temperature stability up to 600 K, an ideality factor close to 1 with a Schottky Barrier Height (SBH) of ~1.5 eV have been demonstrated by electrical measurements. Annealing at higher temperature lead to the deterioration of the contact behaviour in terms of SBH and ideality factor. The reaction between deposited material and diamond or the desorption of oxygen at the interface has been tentatively linked to this phenomenon. In this work, the composition of the WC/O-diamond interfaces annealed at 600 K are analysed by X-ray photoelectron spectroscopy (XPS) depth profile with low energy Ar+ ion sputtering for the first time. The microstructure of the contact is analysed by high-resolution transmission electron microscopy (HR-TEM). The formation of a metastable cubic-WC phase at the interface and the presence of interface oxygen is evidenced. The SBH of the WC/O-diamond contact is estimated by XPS at 1.6 ± 0.2 eV in agreement with I/V measurements.
F. Lloret, D. Eon, E. Bustarret, F. Donatini, and D. Araujo
AIP Publishing
J. Cañas, G. Alba, D. Leinen, F. Lloret, M. Gutierrez, D. Eon, J. Pernot, E. Gheeraert, and D. Araujo
Elsevier BV
J.C. Piñero, J. de Vecchy, D. Fernández, G. Alba, J. Widiez, L. Di Cioccio, F. Lloret, D. Araujo, and J. Pernot
Elsevier BV
A. Jaggernauth, R.M. Silva, M.A. Neto, F.J. Oliveira, I.K. Bdikin, M.P. Alegre, M. Gutiérrez, D. Araújo, J.C. Mendes, and R.F. Silva
Elsevier BV
M. Gutiérrez, D. F. Reyes, D. Araujo, J. P. Landesman, and E. Pargon
Springer Science and Business Media LLC
Gonzalo Alba, M. Pilar Villar, Rodrigo Alcántara, Javier Navas, and Daniel Araujo
MDPI AG
Diamond surface properties show a strong dependence on its chemical termination. Hydrogen-terminated and oxygen-terminated diamonds are the most studied terminations with many applications in the electronic and bioelectronic device field. One of the main techniques for the characterization of diamond surface terminations is X-ray photoelectron spectroscopy (XPS). In this sense, the use of angle-resolved XPS (ARXPS) experiments allows obtaining depth-dependent information used here to evidence (100)-O-terminated diamond surface atomic configuration when fabricated by acid treatment. The results were used to compare the chemistry changes occurring during the oxidation process using a sublayer XPS intensity model. The formation of non-diamond carbon phases at the subsurface and higher oxygen contents were shown to result from the oxygenation treatment. A new (100) 1 × 1:O surface reconstruction model is proposed to explain the XPS quantification results of O-terminated diamond.
Gonzalo Alba, David Eon, M. Pilar Villar, Rodrigo Alcántara, Gauthier Chicot, Jesús Cañas, Juliette Letellier, Julien Pernot, and Daniel Araujo
MDPI AG
Concerning diamond-based electronic devices, the H-terminated diamond surface is one of the most used terminations as it can be obtained directly by using H2 plasma, which also is a key step for diamond growth by chemical vapour deposition (CVD). The resultant surfaces present a p-type surface conductive layer with interest in power electronic applications. However, the mechanism for this behavior is still under discussion. Upward band bending due to surface transfer doping is the most accepted model, but has not been experimentally probed as of yet. Recently, a downward band bending very near the surface due to shallow acceptors has been proposed to coexist with surface transfer doping, explaining most of the observed phenomena. In this work, a new approach to the measurement of band bending by angle-resolved X-ray photoelectron spectroscopy (ARXPS) is proposed. Based on this new interpretation, a downward band bending of 0.67 eV extended over 0.5 nm was evidenced on a (100) H-terminated diamond surface.
Taguhi Yeghoyan, Kassem Alassaad, Véronique Soulière, Gabriel Ferro, Marina Gutierrez, and Daniel Araujo
Wiley
J.C. Piñero, F. Lloret, M.P. Alegre, M.P. Villar, A. Fiori, E. Bustarret, and D. Araújo
Elsevier BV
J. Cañas, J.C. Piñero, F. Lloret, M. Gutierrez, T. Pham, J. Pernot, and D. Araujo
Elsevier BV
Fernando Lloret, Daniel Araújo, David Eon, and Etienne Bustarret
American Chemical Society (ACS)
Dery Torres, Shu Guo, Maria-Pilar Villar, Daniel Araujo, and Rafael Estevez
MDPI AG
Polymer-based composites are becoming widely used for structural applications, in particular in the aeronautic industry. The present investigation focuses on the mechanical integrity of an epoxy resin of which possible damage results in limitation or early stages of dramatic failure. Therefore, a coupled experimental and numerical investigation of failure in an epoxy resin thermoset is carried out that opens the route to an overall micromechanical analysis of thermoset-based composites. In the present case, failure is preceded by noticeable plasticity in the form of shear bands similar to observations in ductile glassy polymers. Thus, an elastic-visco-plastic constitutive law initially devoted to glassy polymer is adopted that captures the rate- dependent yield stress followed by softening and progressive hardening at continued deformation. A general rate-dependent cohesive model is used to describe the failure process. The parameters involved in the description are carefully identified and used in a finite element calculation to predict the material’s toughness for different configurations. Furthermore, the present work allows investigation of nucleation and crack growth in such resins. In particular, a minimum toughness can be derived from the model which is difficult to evaluate experimentally and allows accounting for the notch effect on the onset of failure. This is thought to help in designing polymer-based composites.
RECENT SCHOLAR PUBLICATIONS
MOST CITED SCHOLAR PUBLICATIONS
GRANT DETAILS
1-. Nuevas aleaciones de carbono semiconductoras para una nueva generación de dispositivos electrónicos (CARBOTRONICS-PUENTE)
Universidad de Cádiz (Puerto Real, Cádiz)2020-04 hasta 2021-03|
GRANT_NUMBER: Ref: FEDER-UCA18-106470
2-. Composite de Fibra de carbono (CFRP) conductor térmico y eléctrico por percolación de nano-diamantes (Carbo-Diam)
Junta de Andalucía (Sevilla, Andalucia)2020-02 hasta 2022-01|
GRANT_NUMBER: sol-201800107851-tra
3-. Composite de Fibra de carbono (CFRP) conductor térmico y eléctrico por percolación de nano-diamantes (Carbo-Diam)
Consejería de Economía y Conocimiento. Junta de Andalucía (Sevialla, Andalucía)2019-12 hasta 2022-12|
GRANT_NUMBER: Ref: FDER-UCA-18-107851
4-. Nuevas aleaciones de carbono semiconductoras para una nueva generación de dispositivos electrónicos (CARBOTRONICS-PUENTE)
Consejería de Economía y Conocimeinto. Junta de Andalucía (Sevilla, Andalucía)2019-12 hasta 2021|
GRANT_NUMBER: Ref: FEDER-UCA-18-106586
5-. Fibras de carbono recubiertas de diamante, la nueva generación de composites (CFRP)
Ministerio de Ciencia e Innovación (Cádiz, Andalucía)2018-11 hasta 2020-10|
GRANT_NUMBER: ESP2017 91820 EXP
6-. Architectura 3D de mosfet elaborada in-situ por MPCVD para electrónica de potencia
Ministerio de Economía, Industria y Competitividad, Gobierno de España (Cádiz, Andalucía)2018-01 hasta 2020-12|
GRANT_NUMBER: TEC2017-86347-C2-1-R
7-. Mejora de las prestaciones del laboratorio de preparación de muestras para microscopías (LPM) de los servicios centrales de investigación científica y tecnológica de la universidad de cádiz
Unión Europea (Cádiz, Andalucía)2016-01 hasta 2017-12|Adjudicación
GRANT_NUMBER: UNCA15-CE3256
8-. Green electronics with diamond power devices
European Commission Horizon 2020 (Cádiz, Andalucía)2015-05 hasta 2019-04|Adjudicación
GRANT_NUMBER: SEP-2010-039524
INDUSTRY EXPERIENCE
1-. IBM research center : Zürich, Cantón de Zürich, CH
1992-09-15 hasta 1993-01-15 | Researcher (IBM research center)Employment
2-. Nestec S.A.: Lausanne, Cantón de Vaud, CH
1986-09-02 hasta 1987-08-31 | Researcher (Physics Department)Employment