Contract type: Fixed term contract
Duration: 14 months (+ 22 months + potentially 12 months extension)
Luxembourg Institute of Science and Technology (LIST) is an RTO (Research and Technology Organisation) with an interdisciplinary impact-driven perspective. With more than 200 collaborators, the Materials Research and Technology Department (MRT) of LIST translates cutting-edge materials research into applicable technologies, making a valuable contribution to the Luxembourg and Europe's innovation agenda in Materials Research. The successful candidate will join the Nanomaterials and Nanotechnologies Unit of MRT.
Based on a thorough understanding of the functional properties, the researchers combine their competences to translate the enabling capabilities of nanotechnology/nanomaterials into application-driven solutions in the areas of Smart surfaces, Nanocomposites, Energy, and Micro-Sensing fields.
Recently, a new p-type transparent semiconductor was developed at LIST. This copper-based delafossite presents the highest p-type electric conductivity for a non-doped semiconductor. A peculiar defect, consisting in chained metallic vacancies, was firstly observed in this material and reported by LIST researchers. In this framework, the main objective of the PhD is to determine how the electronic properties of copper-based delafossites might be engineered by manipulating the material nanostructure. The position is part of STEERMOB (Strain-engineering the hole mobility in off-stoichiometric copper chromium delafossite), a research project funded by the Luxembourgish National Research Fund (FNR).
In a primary sense, the basic formula of electrical conductivity (σ=neμ) indicates the carriers’ concentration and their mobility as the only determining factors. These two act as “knobs” that can be turned in order to tune the electrical conductivity towards required values. STEERMOB project deals with the second “knob” namely the electric mobility. In order to improve electric properties, understanding and manipulating the charge transport mechanisms is necessary. This project suggests strain (i.e. mechanical stress) as a tool for manipulating the carrier mobility. Hence, the research questions related: Is it the strain able to control the carrier mobility in copper-based delafossite? The PhD Student will be in charge of fabrication and characterization of semiconducting thin films. These will be synthesized using the Dynamic Liquid Injection Metallo Organic Chemical Vapor Deposition. X-Ray Diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Scanning electron microscopy (SEM) will be used for the characterization of structural and morphological properties. Specific techniques (electrical conductivity, Seebeck coefficient, Hall effect, etc.) will be furthermore used in order to establish interdependencies between optoelectronic properties and the structure at the nano-scale level. The final goal will be to establish how the mechanical stress (internally or externally induced) influences the mobility of the charge carriers in off-stoichiometric copper chromium delafossite.The selected PhD student will be enrolled in the Doctoral School in Science and Engineering (DSSE) of the University of Luxembourg and will develop the research project at LIST’s facilities. She/he will be asked to present the results of her/his research at meetings and international conferences, write scientific articles and give short seminars.
The candidate should: