Missions

The candidate will be studying the properties of, and develop electronic devices based on, a recently discovered ultra-high-mobility semiconductor in epigraphene (SEG) [1]. SEG is grown on macroscopic terraces of silicon carbide (SiC) and exhibits electron mobilities more than ten times higher than silicon. This breakthrough opens the door to a new two-dimensional (2D) electronics platform that is fully compatible with existing microelectronics processing.
SEG overcomes a long-standing limitation of graphene: the absence of a bandgap. As a result, it offers a viable path to 2D semiconductors for nanoelectronics, enabling ultra-low-power tunneling field-effect transistors (TFETs), THz-frequency operation, device miniaturization, and electrostatic top-gate doping.
A unique advantage of SEG is its capacity to be intercalated with a wide range of materials—from small molecules to metals and semiconductors—allowing the creation of novel, air-stable 2D heterostructures [2]. For instance, hydrogen intercalation transforms SEG into quasi-free-standing graphene, while gold intercalation produces a 2D semiconductor.
This postdoctoral project focuses on developing SEG-based TFETs with short channels and subthreshold slopes below 60 mV/decade. It also includes benchmarking device performance and exploring hydrogen- and metal-intercalated SEG as seamless interconnects, emphasizing ballistic edge-state conduction over tens of microns [3]. Low-temperature coherence measurements will be used to probe the poorly understood nature of these edge states, which may pave the way for coherent electronics.
[1] J. Zhao et al., Ultrahigh-mobility semiconducting epitaxial graphene on silicon carbide, Nature 625, 60 (2024); doi:10.1038/s41586-023-06811-0.
[2] C. Riedl et al., Quasi-Free-Standing Epitaxial Graphene on SiC Obtained by Hydrogen Intercalation, Phys Rev Lett 103, 246804 (2009); S. Forti et al., Semiconductor to metal transition in two-dimensional gold and its van der Waals heterostack with graphene, Nature Comm 11, 2236 (2020); doi:10.1038/s41467-020-15683-1.
[3] V.S. Prudkovskiy et al., An epitaxial graphene platform for zero-energy edge state nanoelectronics, Nature Comm 13, 7814 (2022); doi:10.1038/s41467-022-34369-4.

Activités

The candidate will be mainly involved in electronic device design and fabrication, and in low-temperature electronic transport measurements, analysis and interpretation of data. They will also participate in the epigraphene/intercalant /SiC heterostructure fabrication and structural studies and is expected to be an active member of the team, participating in group meetings, journal club, and student mentoring.

Compétences

- PhD in Physics or equivalent
- Experience in clean room and electronic device fabrication techniques (e-beam lithography, dry-etching, metal deposition)
- Experience in electronic measurements
- Knowledge in materials science is appreciated.
- Good communication skills in English (written and spoken).

Contexte de travail

The workplace is at the Georgia Tech/CNRS International Research Lab, School of Physics, Atlanta, Georgia, USA This position is funded by an ANR contract as part of a collaboration between : - The Georgia Tech/CNRS International Research Lab (Atlanta, USA) - Claire Berger and Walt de Heer - The PHELIQS laboratory, INP-CEA in Grenoble - Clemens Winkelmann and Vincent Renard - The Solid State Physics laboratory in Orsay - Antonio Tejeda and Kang Wang The position is located in a sector covered by the Protection of Scientific and Technical Potential (PPST), and therefore requires, in accordance with regulations, that your arrival be authorized by the competent authority of the MESR.

Le poste se situe dans un secteur relevant de la protection du potentiel scientifique et technique (PPST), et nécessite donc, conformément à la réglementation, que votre arrivée soit autorisée par l'autorité compétente du MESR.

Contraintes et risques

There are no known special risks associated with this experimental study. We anticipate intense work with a high potential for success. Access to the laboratory will also require ZRR clearance The candidate will also need to pass ZRR (zone à régime restrictif) clearance.

Informations complémentaires

Van der Waals materials, graphene, nanoelectronics, tunnel field-effect transistors, intercalation, 2D metals.