Are you attending the AVS conference in Nashville next week? Nicolas Boscher, our Scientist of the Week will be there! Read his exclusive interview to Sciengcafe to learn more about his background and recent work.
Dr Boscher’s interview to The Science and Engineering Cafe
Looks like you have gained extensive experience in the field by working at different labs around the world (Université de Rennes 1, France; University College London, UK; MIT, USA; Siemens, Germany). How did these experiences contribute to your professional development and success?
Since my very first internship, I have been involved in various interdisciplinary research projects dealing with thin film technologies and the applications of nanomaterials. My first experiences notably focused on wet chemistry deposition methods for automotive (ENSCR) or piezoelectric transducer (Siemens AG) applications. Following these preliminary research activities in coating technologies, I joined the University College London (UCL) where I learned about Chemical Vapor Deposition (CVD). My time at UCL was also a great opportunity to learn about new materials and new applications of thin films. These various laboratory experiences coupled to the two M.Sc. in Materials Science and Chemistry that I gained from the University of Rennes 1 provided me a solid background to identify several pertinent scientific endeavors that could be overcome using PECVD. In addition, working in various research environments and alongside several world-leading scientists was a great chance for my professional development.
What made you choose plasma as your field of study?
At first, after several preliminary experiences using wet chemistry methods, I was attracted to chemical vapor deposition and had the opportunity to join Prof. Ivan Parkin, whose work had recently contributed to the first commercial self-cleaning product (by Pilkington in 2001). Then, in the last year of my Ph.D., I attended a few talks and despite not realizing yet the multiplicity of plasmas, I got fascinated by plasma-enhanced chemical vapor deposition (PECVD). Luckily, I was further able to join the group of Dr. Patrick Choquet in Luxembourg for a large project (EUR 6 millions) dealing with the “Development of Innovative Surfaces by Means of Optimized Plasma Techniques and Technology Transfer to Industries”.
You have published a lot of research results on atmospheric-pressure plasma-enhanced chemical vapor deposition (AP-PECVD), a fairly new field. In your opinion, what is the current status and potential of developing thin coatings using AP-PECVD?
Over the past ten years, AP-PECVD solutions have extended to a wide range of materials, from polymers to crystalline transition metal oxides and even metallic coatings. Thus, AP-PECVD methods offer promising alternatives to several other low-pressure or thermal CVD processes (e.g. LP-PECVD, iCVD, AP-CVD). Beyond the simple benefits from avoiding the needs for pumping or heating systems, AP-PECVD is allowing the use of wider ranges of injection methods (in the vapor, aerosol, liquid and/or solid state) and precursors, which can lead to the formation of new morphologies (e.g. mesoporous structures, hierarchical roughnesses) and new thin film compositions (e.g. nanocomposites, hybrid coatings) for advanced applications. If AP-PECVD may offer a viable solution for several applications, such as anticorrosion, adhesion and biomolecule grafting, further efforts are required to reach electronic and energy applications.
Describe your latest research work.
Unlike most of my previous research activities, my latest research work dealt with low-pressure CVD (DOI: 10.1002/adma.201601010). This work, undertaken within the group of Prof. Karen Gleason at MIT, investigated the CVD polymerization of metalloporphyrin building units to grow a new kind of dense and defect-free metal–organic covalent network layers for gas separation applications.
The developed strategy relies on the radical polymerizability of the exo-pyrrole double bonds of the metalloporphyrin rings. In accordance with the targeted polymerization reaction and the low vapor pressure of the metalloporphyrin building units, an initiated PECVD (iPECVD) process operated at 5 × 10−3 mbar was selected. The metalloporphyrin building units, vaporized from a heated crucible (step 1), met the radicals formed from the dissociation of a peroxide previously exposed to a remote low power capacitively coupled radio-frequency (RF) plasma (step 2). The resulting hyper-thin (sub-100 nm) and nanoporous MOCN layers (step 3) exhibit outstanding gas-separation performances for multiple gas pairs. In addition, the new MOCN layers are shown compatible with operation at the high transmembrane pressures used in commercial gas-separation processes and the well-known scalability of CVD processes readily allow the preparation of 150 mm diameter membranes.
*****In early November, I will be attending the 63rd AVS International Symposium and Exhibition in Nashville where I will be presenting this latest research work (Plasma Processing for Nanomaterials and 2D Materials).*****