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Konstantinos Pantzas
Tel: (+33) 1 69 63 60 54
Groupe: Elaboration et Physique des Structures Epitaxiées , Groupe d'Optique des Structures Semi-conductrices
Actions: CPOI , AMoN

Puce Short bio

After completing a Dual Master's Degree between Supélec and the Georgia Institute of Technology specialized in micro- and optoelectronics (May 2009), I embarked upon a dual Ph.D. program between the Georgia Institute of Technology and the University of Lorraine. I obtained my Ph.D. in Materials Science from the University of Lorraine in January 2013, on the topic MOCVD growth and characterization of indium gallium nitride for photovoltaic applications. I then accepted a 2-year post-doctoral fellowship in electron microscopy in LPN, where I currently work under the supervision of Dr. Gilles Patriarche , while simultaneously completing my Ph.D. in Electrical and Computer Engineering from Georgia Tech.

Most of my current work revolves around the structural, mechanical, and electrical characterization of InP/Si wafer-fused interfaces. This work is carried out within the framework of ANR P2N project COHEDIO. The project investigates oxide-free wafer-bonding of InP to Si for advanced Photonic Integrated Circuits that fully integrate the mechanical, optical, thermal, and electrical properties of the two semiconductors.

A copy of my curriculum vitae can be found here, and a copy of my full list of publications here.

Puce Research Interests

My current research interests evolve around the following topics:

A brief description on these topics, as well as a few examples from recent publications and ongoing work are given below.

Puce Quantification of the HAADF contrast using EDX

In high-angle annular dark-field (HAADF) STEM, the image intensity is proportional to the STEM specimen thickness, the density of the material being imaged and its composition. With careful specimen preparation and using a few EDX measurements to calibrate contrast variations, it is possible to reconstruct chemical mappings from HAADF-STEM images. These mappings combine the chemical precision of EDX and the resolution of HAADF-STEM, opening the path towards atomically-resolved, quantitative chemical mappings of samples observed in a STEM.


Fig.1. (a) HAADF-STEM image of an indium gallium nitride epilayer grown on GaN using MOVPE presenting nanometer-scale flucutations in the indium composition; (b) corresponding chemical mapping, quantifying the fluctuations of the indium composition. Results published in Nanotechnology ( link to article).

Such mappings can be correlated to other analytic transmission electron microscopy techniques, such cathodoluminescence in a STEM or dark-field electron holography, to help interpret optical or structural data obtained from these techniques.


Fig.2. (a) HAADF-STEM image of an InGaN/GaN sample; (b) corresponding chemical mapping; (c-f) energy-filtered emission spectra obtained from Cathodoluminescence in a STEM in the same region as in (a). Results currently under review for publication.

Additional applications sub-nanometrically resolved chemical mappings of Quantum Cascade Laser Structures or Nanowires that are useful for basic growth studies.


Fig.3. (a) HAADF-STEM image of an InGaAs/InAlAs THz QCL structure; (b) corresponding chemical mapping; (c) HAAF-STEM image of a GaAs nanowire with a AlGaAs wells as markers;(d) Corresponding chemical mapping.

Puce Publications dans des journaux

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