Missions

The candidate will be involved in the development of an experimental technique that combines the spatial resolution of scanning probe microscopy with the temporal resolution of a femtosecond optical pump-probe assembly, for applications in the characterisation of two-dimensional materials and vdW heterostructures.

Activities

Low-dimensional systems, in particular 2D materials, are benefiting from considerable efforts to develop intrinsic encapsulated systems, such as 2D transition metal dichalcogenides (TMDCs)[1] or CdSe colloidal nanoplatelets[2], with minimal spatial inhomogeneity and broadening effects. These remarkable structural and optical properties make 2D materials ideal candidates for replacing conventional materials in optoelectronic applications. However, there is as yet no instrumental technique for characterising charge carriers with combined high spatial and temporal resolution. This is the main objective of the project (INFERNO ANR-22-CE42-0015-01): the development of an innovative instrument capable of performing in-situ multi-scale spatial and temporal analysis of the basic physical mechanisms governing the operation of optoelectronic materials and devices. This technique enables the local injection of charge carriers using a multi-probe scanning tunneling microscope coupled to pulsed laser excitation and optical detection in order to reveal the physical mechanisms that limit the electroluminescence of nanostructure-based devices.
This postdoctoral project will focus on two areas of work:
- Developing the instrument's capabilities by working on the coupling of optical/electronic excitation/detection techniques in ultra-high vacuum: dynamic photo-transport at nanometric resolution, electroluminescence of nano-junctions, etc.;
- Proving the instrument's ultimate performance by characterising samples of two-dimensional materials and heterostructures.
References:
1. Cadiz, F. et al. Excitonic linewidth approaching the homogeneous limit in MoS2-based van der Waals heterostructures. Phys. Rev. X7, 021026 (2017).
2 Ithurria, S. et al. Colloidal nanoplatelets with two-dimensional electronic structure. Nat. Mater.10, 936-41 (2011).

Skills

A PhD in physics, solid state physics, semiconductor physics, engineering or a relevant field. The candidate should demonstrate initiative, a high capacity for work, an enthusiasm for science and an appetite for experimental work. A good command of English and excellent oral and written skills are required. Knowledge of scanning tunneling microscopy, atomic force microscopy, scanning electron microscopy, ultra-high vacuum and pump-probe spectroscopy is required, experience is a plus. Any engineering skills would be highly appreciated.

Work Context

The candidate will join the IEMN's 'Physics of nanostructures and quantum devices' team, which comprises 4 PhD students, 3 CNRS researchers, 5 teacher-researchers and 2 research engineers (more information at https://www.iemn.fr/la-recherche/les-groupes/physique/nanostructures-quantum). The IEMN is a joint research unit located on the campus of the University of Lille with a staff of 450. Ideally located just 1 hour by train from Paris, London and Brussels, the IEMN is one of the 5 major French technology centres in the RENATECH network. In addition to internal requests (22 research groups), the multi-physics characterisation platform welcomes requests for analyses from the University of Lille, academic partners and industry in a stimulating multidisciplinary environment. In this context, the laboratory supports technological developments in the fields of scanning probe microscopy and optics. It is supported by in-house prototyping services, access to fablabs and strong links with several engineering schools. The position is located in a sector covered by the protection of scientific and technical potential (PPST), and therefore requires, in accordance with the regulations, that your arrival be authorised by the competent authority of the MESR.

The position is located in a sector under the protection of scientific and technical potential (PPST), and therefore requires, in accordance with the regulations, that your arrival is authorized by the competent authority of the MESR.

Constraints and risks

Short-term travel in France and abroad is to be expected.