2D semiconductor materials grown on graphene/metal/SiC

Published : 11 October 2019

Quantum materials (QMats) are prime candidates for next-generation energy-efficient technologies, such as topological quantum computing, quantum sensing, and neuromorphic computing. In particular van der Waals 2D materials exhibit a compellingly wide range of exotic and potentially useful properties such as charge density waves, topological insulator edges, etc… More generally, van der Waals epitaxy is a way to stabilize new 2D allotropes of traditionally 3D semiconductors and magnets exhibiting amazing properties, making them of current interest. Graphene, as a parangon of 2D materials, is now widely used as a substrate for performing van der Waals epitaxy of 2D materials.

In the PHELIQS/NPSC laboratory we have developed an expertise on the epitaxial growth of III-V semiconductors (GaN, AlN and InN) for optoelectronics applications. This expertise includes the use of graphene/SiC substrates allowing in principle to perform van der Waals epitaxy of those III-V semiconductors. One key result illustrated in the figures below is the demonstration that a bi-layer of metal (In or Ga) can be intercalated at the graphene/SiC interface. This provides a semiconductor/metal/graphene sandwich to be used as a “platform” for subsequent  growth of 2D III-N semiconductors and metal dichalcogenides, with an integrated metallic electrode.

We propose a Master training on the growth of such 2D materials by molecular beam epitaxy on this van der Waals platform. The intercalated SiC/metal/graphene substrates will be prepared for this purpose, before subsequent deposition of layered nitride semiconductors. The samples will be characterized by scanning electron microscopy, AFM, high resolution electron microscopy, photoluminescence spectroscopy. We are looking for a student strongly motivated by epitaxial growth as well as by material science in general. The trainee will benefit from the already established collaborations in and outside the group (H. Okuno, IRIG/MEM/LEMMA, M. Jamet, IRIG/SPINTEC, A. Cros, University of Valencia, Spain).

[1] N. Feldberg, Oleksii Klymov, Nuria Garro, Ana Cros, Hanako Okuno, M. Gruart and B. Daudin, Nanotechnology 30 (2019) 375602


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