Biography: Born in Barcelona in 1966, Jordi Llorca graduated and earned his PhD in Chemistry at the University of Barcelona, where he was later appointed Associate Professor. In 2005, he joined the Technical University of Catalonia (UPC) as Professor and in 2014 he became Full Professor as Serra Húnter Fellow. He has conducted research at the Univ. of New Mexico (US), CNRS (France) and has been Invited Scholar at the Univ. of Udine (Italy), Univ. of Auckland (New Zealand) and CONICET (Argentina). He has received the Distinction of Generalitat de Catalunya to the Promotion of the University Research in 2003, the Humbert Torres Prize in 2003 and the ICREA Academia in 2009 and in 2014. From 2011 to 2014 he has been Director of the Institute of Energy Technologies (INTE) at UPC and currently he is Director of the Centre for Research in NanoEngineering (CRnE) at UPC. He has published over 220 scholarly articles and authored 9 patents. Prof. Jordi Llorca is working on the design and manufacture of new devices at the nanoscale for conducting chemical and photochemical reactions aimed at the generation, purification and separation of hydrogen for portable fuel cells as well as other processes related to energy and environmental applications.
Title of Speech: Nanoengineered catalysts for generating hydrogen from ethanol
Abstract: In the viewpoint of hydrogen production via reforming processes, compared to the most commonly derived fossil feedstocks used industrially nowadays for producing hydrogen (natural gas, gasoline, etc.), alcohols represent an emerging and alternative source since they can be produced renewably from biomass. Among them, bioethanol constitutes an important source that seems to be particularly suitable due to its easy and broadly implemented production from a variety of plants. The highest hydrogen production is obtained by the steam reforming of ethanol (ESR), formally written as C2H5OH+3H2Oà6H2+2CO2. An efficient catalyst for this reaction has to dissociate the C-C bond, maintain low the CO concentration (involved in the water gas shift equilibrium) and be stable under catalytic operation (avoid coke accumulation). Noble metals fulfill these requirements at high temperature, whereas cobalt-based catalysts are less active and prone to carbon deposition, but they are very selective because the reforming temperature can be significantly lower. Thus, a precise design of catalysts is still required to carry out the ESR. Here I will discuss about the nanoengineering of bimetallic RhPd nanoparticles supported over a reducible oxide (nanoshaped CeO2) from fundamental structural (HRTEM) and operando studies (Ambient Pressure XPS) as well as layered Co structures for the ESR. The specific role of oxidation states and the development of core-shell structures on catalytic performance will be presented as well as the technical developments towards its implementation in catalytic wall reactors, membrane reactors and microreactors for practical application.
Biography: Dr. Jean-Jacques Delaunay (http://scale.t.u-tokyo.ac.jp) is an Associate Professor at School of Engineering, The University of Tokyo. He received his PhD degree from the Strasbourg University. He has worked for research institutions in the fields of nanotechnology and solar energy in France, Germany and Japan. He conducts research on the synthesis of micro/nano materials with controlled structures and functionalities for sensing and energy conversion. He also conceives plasmonic nanostructure arrays to enhance sensitivity of detectors and light collection of solar energy conversion devices. His current research projects include plasmonic nano-cavities for optical sensing and nanostructured photoelectrodes for water splitting with sun light. He has co-authored more than 100 scientific publications.
Title of Speech: Nanoengineered catalysts for generating hydrogen from ethanol
Abstract: The optical response of subwavelength plasmonic structures has been used to monitor changes in their physical, chemical, and biological environments. The detection of this response in the far field is governed by the near-field properties of plasmon resonances. Although the plasmonic structures offer high performance in sensing, their micro integration on chips is difficult because of the readout in the far field. As such, structures that form an electrical micro-circuit and directly monitor the optical near-field variation without resorting to far-field optical detection would be more desirable. We present an electronically readable photocapacitor based on a plasmonic nanochannel structure, which offers both high confinement and efficient light collection together with high spectral resolution and a large modulation capability. The proposed structure consists of semiconducting nanochannels sandwiched between plasmonic cavities and monitors the change in incident light wavelength with high spectral resolution and large impedance modulation. In this nanochannel structure, three types of plasmon resonances including localized surface plasmonic resonance, vertical channel surface plasmonic resonance and horizontal surface plasmonic resonance are coupled. Light is thus strongly and selectively trapped in the nanochannels and highly confined at the semiconductor-metal interfaces. Due to the confinement, light is efficiently converted into photocarriers at these interfaces, thus varying the electrical impedance of the structure. The capacitance modulation of the structure in response to light produces a large light-to-dark contrast ratio. As a result of significant capacitance modulation, the spectral selectivity of the electrical response (~20 nm) is as high as that of the reflectance spectrum measured in the far-field.
Prof. Witold Daniel Dobrowolski
Institute of Physics Polish Academy of Sciences, Warsaw, Poland
Dobrowolski is a Professor at the Institute of Physics of the
Polish Academy of Sciences. He has spent nearly all his academic
career at this Institute. He conducted research on narrow gap
semiconductors and diluted magnetic semiconductors (called also
semimagnetic semiconductors). His principal scientific interests
are: (a) Physics of crystal growth and material processing of
compound semiconductors, alloys, and semimagnetic crystals;
(b) Electronic transport phenomena, magneto- and quantum transport in semiconductors;
(c) Narrow-gap semiconductors - band structure, impurity levels, transport phenomena;
(d) Semimagnetic semiconductors - electronic and magnetic properties, magnetic phase diagram.
Current research interest covers magnetic interactions in III-V, II-VI, and IV-VI compounds (bulks, thin films, and nanoparticles), mutual interactions between magnetic ions and free carriers.
He has co-authored more than 200 scientific publications and a few book chapters.
He is editor-in-chief of Acta Physica Polonica A.
Title of Speech: II-IV-V2 diluted magnetic semiconductors - homogeneous vs. composite system
Abstract: In this paper, we
will review our recent studies of the magnetic and transport
properties of the AII1-xMnxBIVCV2
diluted magnetic semiconductors (DMS). The non-magnetic
equivalents of the studied systems have many interesting
properties. The direct energy gap at the Γ point of the
Brillouin zone and large nonlinear optical coefficients of this
system make this material suitable for applications in nonlinear
optics. The nondegenerate top of the valence band makes this
compound an efficient source of spin polarized photoelectrons.
The energy gaps for three studied compounds are Eg
= 0.34 eV for ZnSnAs2, Eg
= 0.53 eV for CdGeAs2, and Eg
= 1.15 eV for ZnGeAs2,
respectively. Moreover, it may be noted that ZnGeAs2
is nearly lattice matched with GaAs what makes it compatible
with the existing GaAs-based devices.
Recently, we have been studying magnetic properties of quaternary and quinary II IV-V2 DMS with varying concentrations of different magnetic and non-magnetic cations. The limit of alloying of Cd1-xMnxGeAs2 and Zn1-xMnxGeAs2 compounds indicates that the solubility limit of Mn ions inside the chalcopyrite lattice is around a few molar percent. The detailed studies of the magnetic properties of Zn1-xMnxGeAs2 samples show that the Mn distribution is random in the cation sites of the host lattice only for the sample with the lowest Mn-content, x = 0.003. For the samples with higher content of Mn, we observed clusters of different types, from the non-random distribution of magnetic ions in the host lattice to precipitates with the crystalline structure different from that of the host. The size of such precipitates varied from 200 nm to 20 µm. Depending on the type and size of clusters, we observed different magnetic properties of the compounds, such as paramagnetic, spin-glass, spin-glass-like, or ferromagnetic states. For example, Zn1-xMnxGeAs2 compound
Prof. Tatiana Perova
Department of Electronic and Electrical Engineering, Trinity College Dublin, The University of Dublin, Ireland
Biography: Prof. Perova completed her PhD at Leningrad State University in 1979. She joined the staff of Vavilov State Optical Institute (St. Petersburg, Russia) in 1979, where she was involved in the characterization of condensed matter using far-infrared and Raman spectroscopy. In 1998 Prof. Perova took a position of the Research Director of Microelectronic Technology Laboratory (MTL) at Trinity College Dublin and from 2007 she is the Director of MTL. Since 2011 she is a Fellow of Trinity College Dublin and since 2013 she is a Fellow Emeritus. Prof. Perova’s research interests are principally related to the optical characterization of condensed matter, with an emphasis on the analysis of the composition, stoichiometry, molecular orientation, stress and strain in amorphous solids, liquid crystals, photonic crystals and semiconductors. She has over 270 publications in books and referred journals. Prof. Perova has given numerous invited talks at Universities and Research Institutes in Europe, Russia, Australia and Mexico and several invited and keynote talks at International Conferences. Prof. Perova is acting as a Reviewer Editor for the journal Frontiers: Frontiers in Materials and is a member of the Editorial Board of Asian Chemistry Letters journal.
Title of Speech: Borosilicate glass nanolayer as a spin-on dopant source for application in solar cells
Abstract: Borosilicate glass
is a potential dopant source for producing shallow boron
junctions by the use of proximity rapid thermal diffusion.
Interest in this technique has increased recently due to its
application to the manufacture of solar cells. A borosilicate
gel is spun onto a silicon wafer and the layer is rapidly
thermally annealed to convert it to a borosilicate glass (BSG).
Fourier transform infrared (FTIR) spectroscopy, spectroscopic
ellipsometry and sheet-resistance measurements have been used to
understand and subsequently optimise the conversion of the gel
to a BSG nanolayer. Physical properties of the thin, spun-on
layer, such as thickness, refractive index and porosity, were
monitored. The optimum conversion step involved rapid thermal
annealing for 45 s at 900 ºC. This avoided any boron loss from
the BSG layer during the thermal processing step. The position
of the B-O stretching vibration around 1370 cm-1 was found to be
sensitive to boron outdiffusion and it is suggested that FTIR
spectroscopy provides a simple method for monitoring the
outdiffusion of boron from the spin-on dopant nanolayer. Further
FTIR studies using p-polarised light at oblique incidence
revealed, for the first time, the LO-TO phonon splitting of the
B-O stretching vibration band in the glassy layer. Investigation
of the stability of BSG layers over long periods showed that
unstabilised (or undensified) BSG films demonstrate a dramatic
loss of boron over 6 months.