Lucia Beamline : USIAS

SOLEIL is the French synchrotron radiation centre, located on the Saclay plateau near Paris. SOLEIL is a multidisciplinary instrument and research laboratory, whose mission is to conduct research programmes using synchrotron radiation, to develop state-of-the-art instrumentation on the beamlines and to make them available to the scientific community. The SOLEIL synchrotron, a unique tool for both academic research and industrial applications, opened in 2008. It is used annually by several thousand French and foreign researchers, across a wide range of disciplines such as physics, biology, chemistry, astrophysics, environmental and Earth sciences, etc. SOLEIL relies on a source of radiation that is remarkable both in terms of brightness and stability. This Very Large Research Infrastructure, partner of the University of Paris-Saclay, is a "civil" company jointly founded by the CNRS and the CEA.

Hybrid Organic-Inorganic Perovskites (HOIPs) have been the subject of increasing studies in the last decade, from both fundamental and applied perspectives. This interest is driven by the peculiar properties that they display in relation to light emission and absorption and the corresponding applications in light capture and conversion. With a general structure following the formula ABX3 (A being an organic monovalent alkyl ammonium cation, B a divalent metal cation and X a halide anion) their electronic and stability properties can be tuned by changing the nature of the organic cation. In particular, the length of the organic chain in the alkyl ammonium cation can have drastic effects on the secondary structure of these materials, hence on their properties. Up to now, the synthesis of these hybrid materials is not well understood, preventing the control of the final products properties.

A research grant was attributed by the USIAS (University of Strasbourg Institute for Advanced Studies) to Benedikt Lassalle and Ovidiu Ersen in 2022, in order to study the synthesis of HOIPs, using a combined TEM and XAS in situ approach. The aim of this project is to observe intermediate structures on the way to HOIPs and understand their evolution towards the final structures, in order to optimize their properties. Our strategy follows two steps : i) develop microfluidic tools that can be used to probe a chemical reaction under in situ conditions using both TEM and XAS (and potentially SAXS/WAXS as well) and ii) establish the reaction landscape for the synthesis of HOIPs by the Ligand Assisted Reprecipitation (LARP) method. The well-known MAPbI3 (MA=methylammonium) will be used to establish the method, while other lead-free systems will be studied in a second step.

We are looking for a highly motivated candidate with a PhD in experimental sciences (physics, chemistry, material sciences) and a strong interest in instrumental developments. A demonstrated experience in either electron microscopy, X-ray spectroscopy or microfluidic fabrication is required. Knowledge of (hybrid) perovskites synthesis would be highly appreciated, while experience in synthesis and material characterization is mandatory. The ability to work in a collaborative team with several partners in different locations is expected. Excellent communication skills (both written and oral) in English are required.

The post-doctoral fellow will be hired by and located at the ICPMS (Surface and Interface team) in Strasbourg, with frequent sessions in SOLEIL to develop microfluidic devices and collect XAS and SAXS/WAXS data.

Questions and applications should be sent to:

Dr. Benedikt Lassalle : benedikt.lassalle@synchrotron-soleil.fr

Pr. Ovidiu Ersen : ersen@ipcms.unistra.fr

IPCMS is a CNRS/UNISTRA joint laboratory, dedicated to the physics and chemistry of materials, located on the Cronenbourg campus in Strasbourg.

SOLEIL is the French national synchrotron facility, located on the Paris-Saclay campus. It is a multi-disciplinary instrument dedicated to the study of matter in all its forms.

Duration : 2-year position (starting early 2023)

Location : IPCMS, Strasbourg, France and Synchrotron SOLEIL, Paris-Saclay, France