François Tran Van

Prof. Dr. François Tran Van


Research Focus & Metrics

Academic Career Length

21Years (2006-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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26 June 2012 in Discover Nano
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TDThomas Defforge
Thomas Defforge
MCMarie Capelle
Marie Capelle
FVFrançois Tran Van
François Tran Van
GGGaël Gautier
Gaël Gautier
The study of an innovative fluoropolymer masking layer for silicon anodization is proposed. Due to its high chemical resistance to hydrofluoric acid even under anodic bias, this thin film deposited by plasma has allowed the formation of deep porous silicon regions patterned on the silicon wafer. Unlike most of other masks, fluoropolymer removal after electrochemical etching is rapid and does not alter the porous layer. Local porous regions were thus fabricated both in p+-type and low-doped n-type silicon substrates.

18 February 2014 in Polymer International
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MDMartial Degbia
Martial Degbia
BSBruno Schmaltz
Bruno Schmaltz
Johann BoucléJohann Bouclé
Johann Bouclé
JGJuozas V Grazulevicius
Juozas V Grazulevicius
FVFrançois Tran Van
François Tran Van

6 August 2018 in Materials
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DBDaphné Berthier
Daphné Berthier
MDMarie-Pierre Deffarges
Marie-Pierre Deffarges
NBNicolas Berton
Nicolas Berton
MVMathieu Venin
Mathieu Venin
FLFlorian Lacroix
Florian Lacroix
SMStéphane Méo
Stéphane Méo
The present study reports on the use of three types of polyhedral oligomeric silsesquioxanes (POSS) nanoparticles with various organic substituents as fillers in a fluoroelastomer (FKM). A series of/POSS elastomer composite thin films is prepared. Microstructural SEM/TEM (scanning electron microscopy/transmission electron microscopy) imaging reveals a dispersion state allowing the presence of micron-sized domains. The influence of POSS content is studied in order to optimize thermal stability and mechanical properties of the composite thin films. Both POSS-A (with an acryloyl functional group and seven isobutyl substituents) and POSS-P (with eight phenyl substituents) lead to higher thermal stability and modulus of the composites, with respect to the unfilled FKM terpolymer matrix. covalent grafting of POSS-A onto the FKM network is found to play a critical role. Enhanced storage modulus in the rubbery plateau region (+210% at 200 °C for 20 phr) suggests that POSS-A is particularly suitable for high temperature applications.

30 July 2021 in Materials
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FAFatima Al-Zohbi
Fatima Al-Zohbi
Fouad GhamoussFouad Ghamouss
Fouad Ghamouss
BSBruno Schmaltz
Bruno Schmaltz
MAMohamed Abarbri
Mohamed Abarbri
MZMustapha Zaghrioui
Mustapha Zaghrioui
FVFrançois Tran Van
François Tran Van
Polyaniline (PANI) was synthesized using oxidative polymerization in a mixture of water with pyrrolidinium hydrogen sulfate [Pyrr][HSO4], which is a protic ionic liquid PIL. The obtained PANI (PANI/PIL) was compared with conventional PANI (PANI/HCl and PANI/HSO4) in terms of their morphological, structural, and storage properties. The results demonstrate that the addition of this PIL to a polymerization medium leads to a fiber-like morphology, instead of a spherical-like morphology, of PANI/HSO4 or an agglomerated morphology of PANI/HCl. In addition, PAN/PIL exhibits an improvement of the charge transfer kinetic and storage capability in H2SO4 1 mol·L−1, compared to PANI/HCl. The combination of PANI/PIL and graphene oxide (GO), on the other hand, was investigated by optimizing the PANI/GO weight ratio to achieve the nanocomposite material with the best performance. Our results indicate that the PANI/PIL/GO containing 16 wt% of GO material exhibits a high performance and stability (223 F·g−1 at 10 A·g−1 in H2SO4 1 mol·L−1, 4.9 Wh·Kg−1, and 3700 W·Kg−1 @ 10 A·g−1). The obtained results highlight the beneficial role of PIL in building PANI and PANI/GO nanocomposites with excellent performances for supercapacitor applications.

11 November 2022 in Materials
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FBFatiha Bouihi
Fatiha Bouihi
BSBruno Schmaltz
Bruno Schmaltz
FMFabrice Mathevet
Fabrice Mathevet
DKdavid kreher
david kreher
JFJérôme Faure-Vincent
Jérôme Faure-Vincent
MAMohamed Abarbri
Mohamed Abarbri
Donor–acceptor (D–A) small molecules are regarded as promising hole-transporting materials for perovskite solar cells (PSCs) due to their tunable optoelectronic properties. This paper reports the design, synthesis and characterization of three novel isomeric D-π-A small molecules PY1, PY2 and PY3. The chemical structures of the molecules consist of a pyrazolo[1,5-a]pyrimidine acceptor core functionalized with one 3,6-bis(4,4′-dimethoxydiphenylamino)carbazole (3,6-CzDMPA) donor moiety via a phenyl π-spacer at the 3, 5 and 7 positions, respectively. The isolated compounds possess suitable energy levels, sufficient thermal stability (Td > 400 °C), molecular glass behavior with Tg values in the range of 127–136 °C slightly higher than that of the reference material Spiro-OMeTAD (126 °C) and acceptable hydrophobicity. Undoped PY1 demonstrates the highest hole mobility (3 × 10−6 cm2 V−1 s−1) compared to PY2 and PY3 (1.3 × 10−6 cm2 V−1 s−1). The whole isomers were incorporated as doped HTMs in planar n-i-p PSCs based on double cation perovskite FA0.85Cs0.15Pb(I0.85Br0.15)3. The non-optimized device fabricated using PY1 exhibited a power conversion efficiency (PCE) of 12.41%, similar to that obtained using the reference, Spiro-OMeTAD, which demonstrated a maximum PCE of 12.58% under the same conditions. The PY2 and PY3 materials demonstrated slightly lower performance in device configuration, with relatively moderate PCEs of 10.21% and 10.82%, respectively, and slight hysteresis behavior (−0.01 and 0.02). The preliminary stability testing of PSCs is also described. The PY1-based device exhibited better stability than the device using Spiro-OMeTAD, which could be related to its slightly superior hydrophobic character preventing water diffusion into the perovskite layer.

9 July 2012 in Discover Nano
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TDThomas Defforge
Thomas Defforge
JBJérôme Billoué
Jérôme Billoué
MDMarianne Diatta
Marianne Diatta
FVFrançois Tran Van
François Tran Van
GGGaël Gautier
Gaël Gautier
In this article, the physico-chemical and electrochemical conditions of through-silicon via formation were studied. First, macropore arrays were etched through a low doped n-type silicon wafer by anodization under illumination into a hydrofluoric acid-based electrolyte. After electrochemical etching, ‘almost’ through-silicon macropores were locally opened by a backside photolithographic process followed by anisotropic etching. The 450 × 450-μm² opened areas were then selectively filled with copper by a potentiostatic electrochemical deposition. Using this process, high density conductive via (4.5 × 105 cm−²) was carried out. The conductive paths were then electrically characterized, and a resistance equal to 32 mΩ/copper-filled macropore was determined.