PhD Fellowship in Chemistry/ Materials Sciences (M/F) :Scintillating Materials by 3D printing

Job Description

Thesis Subject

Nuclear reactors, reprocessing plants, and decommissioning operations release gaseous effluents or aerosols containing radionuclides. Monitoring these emissions is crucial for environmental and radiological safety. However, current technologies do not enable real-time detection of low-activity volatile radionuclides.
To address this challenge, our goal is to develop porous scintillator monoliths through which gases containing radioisotopes such as tritium (³H) or krypton (⁸⁵Kr) can flow. As the gas circulates, radioactive atoms emit beta radiation, triggering light flashes in the scintillator material. These light emissions can then be easily converted into electrical signals, providing a rapid, continuous, and sensitive method for detecting radioactive gases.
The chemical challenge lies in synthesizing a monolith (a single-piece material) with the following ideal properties:

High porosity to allow the circulation of various types of radioactive fluids. We aim to create a monolith with both macroporous (channels 0.2–1 mm in diameter) and mesoporous (pore sizes below 100 nm) structures.
Excellent scintillation properties, particularly a high radioluminescence light yield.
Maximal transparency to ensure that luminescence flashes can be detected deep within the monolith.
To achieve this, we propose an innovative synthesis of cerium-doped yttrium silicates (scintillator material) using 3D printing. At ICGM, we have already developed a 3D printing method for mesoporous silica monoliths using photo-crosslinkable silica nanocage inks. The printing process, based on Digital Light Processing (DLP), uses UV light to polymerize the inks layer by layer, enabling the fabrication of monoliths with controlled and varied geometries. We have also demonstrated the incorporation of metal ions into the ink and, consequently, into the final monolith. In this PhD project, these metal ions will be yttrium (Y³⁺) and cerium (Ce³⁺) cations. The printed monoliths will then undergo high-temperature thermal treatment to induce the crystallization of cerium-doped yttrium silicate (Y₂Si₂O₇:Ce), a material renowned for its excellent scintillation properties, emitting intense blue luminescence under ionizing radiation. We will ensure that the monolith's porosity is preserved after thermal treatment to maintain gas flow and optimal detection.
The PhD student will learn the synthesis of nanomaterials and their integration with 3D printing techniques. The synthesized materials will be characterized using structural techniques (XRD, BET), electron microscopy (TEM, SEM), UV-Vis absorption spectroscopy, and photo- and radio-luminescence.
This thesis will be conducted in close collaboration with the Institut Lumière Matière (ILM) in Lyon, where scintillation measurements will be performed, and with the Laboratoire National Henri Becquerel (LNHB) at CEA Saclay, where tests for detecting radioactive fluids will be carried out on the porous scintillator monoliths produced during the thesis.
The ideal candidate should be enthusiastic, motivated, and enjoy working in a team with collaborators from diverse scientific backgrounds. Proficiency in English is required.
Gross salary: €2,300/month (36 months) – Contract start: October 2026
References:

[1] R. Marie-Luce et al., Nat. Photon., Sept. 2024, doi: 10.1038/s41566-024-01507-x.

[2] T. Gaillard et al., Adv. Funct. Mater., p. 2509897, June 2025, doi: 10.1002/adfm.202509897.

Your Work Environment

The thesis will be carried out within the framework of the "Sciences Chimiques Balard" Doctoral School and will take place at the Institut Charles Gerhardt de Montpellier (ICGM). ICGM is a large research unit (with approximately 200 permanent members) covering all major fields of chemistry. The institute is located in the new Balard Recherche building on the CNRS campus, Route de Mende.
The thesis will be co-supervised by Aurélie Bessière from the D1 department (Molecular Chemistry and Materials) and Tangi Aubert from the D3 department (Porous and Hybrid Materials). It is part of the ANR PriSci project, which brings together collaborators from ILM and CEA. During the thesis, the PhD student will visit ILM in Lyon and CEA in Saclay to conduct measurements and discuss results. They will also present their findings at international conferences.

Compensation and benefits

Compensation

2300 € gross monthly

Annual leave and RTT

44 jours

Remote Working practice and compensation

Pratique et indemnisation du TT

Transport

Prise en charge à 75% du coût et forfait mobilité durable jusqu’à 300€

About the offer

About the CNRS

The CNRS is a major player in fundamental research on a global scale. The CNRS is the only French organization active in all scientific fields. Its unique position as a multi-specialist allows it to bring together different disciplines to address the most important challenges of the contemporary world, in connection with the actors of change.

CNRS

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