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Reference : UMR7252-JOHBOU-001
Workplace : LIMOGES
Date of publication : Monday, August 05, 2019
Scientific Responsible name : Bernard Ratier
Type of Contract : PhD Student contract / Thesis offer
Contract Period : 36 months
Start date of the thesis : 1 October 2019
Proportion of work : Full time
Remuneration : 2 135,00 € gross monthly
Description of the thesis topic
Halide perovskite are highly promising semiconducting materials due to their excellent electronic properties and their ability to be processed from solution using various low-cost printing technologies. They enabled a very fast development of high efficiency solar cells or light-emitting devices (such as light-emitting diodes or LED), even if several issues remain to be addressed towards stable and environment-friendly components. In this context, the PhD thesis is targeting a fine control of the interfacial properties of perovskite LED in order to improve both their performance and lifetime. Potential applications are related for example to visible light communications (VLC), even if the proposed strategies are relevant for photovoltaic energy conversion as well.
The main objective of the thesis is to exploit the various strategies proposed by the XLIM Institute or his partners, to realize perovskite LED and to evaluate their optoelectronic performance under static or dynamic regimes considering the targeted applications for VLC. The successful applicant will have to adapt the charge transport layers usually used in the devices, in order to optimize and enhance their optoelectronic response: luminance, emission pattern, external quantum efficiency, bandwidth, etc. A special attention will be paid on strong injection regimes, in an attempt to demonstrate electrically-driven light emitting devices. Another aspect will be devoted to the development of interfacial inks in order to enable device printing on flexible substrates, in order to simplify their integration.
The CNRS is a public body under the responsibility of the French Ministry of Education, Research and Innovation. Founded in 1939, it covers all scientific disciplines: humanities and social sciences, biological sciences, nuclear and particle physics, information sciences, engineering and systems, physics, mathematical sciences, chemistry, earth sciences and astronomy, ecology and environment. The eighteen CNRS regional delegations are the main interlocutors of the organization's partners throughout the country. They have a role of management and local support of laboratories spread over the territory. They help in particular to set up industrial projects and European programs. In this context, the Regional Delegation Center Limousin Poitou-Charentes covers 2 administrative regions with 67 laboratories or units, distributed in 7 departments and associated with 5 universities.
The Doctoral School n°610, Sciences and Engineering of Systems, Mathematics and Computer Science (SISMI) is directed by Professor Bernard Jarry. It covers the following disciplines: mathematics, microwaves, photonics, computer science, images, automatisms and their interactions. It delivers the following thesis references: Mathematics and Applications, Computer Science and Applications, High Frequency Electronics, Photonics and Systems, Image, Signal and Automation. It is attached to 4 institutions (COMUE Leonard de Vinci, University of Limoges, University of Poitiers and ASE / ENSMA in Poitiers). It relies on 3 partner laboratories: XLIM, LMA and LIAS. 250 doctoral students are enrolled in the SISMI doctoral school.
XLIM is a research laboratory (UMR 7252) linking the CNRS and the University of Limoges. It has a strong expertise in various topics such as electronics and microwave, optics and photonics, mathematics, computer and image, CAD, space, telecom networks, secure environments, bio-engineering, new materials, energy and imaging. XLIM is a multidisciplinary research institute with several geographical locations and more than 440 people such as professors, CNRS researchers, engineers, technicians, post-docs, PhD students and administrative staff (website: www.xlim.fr).
The work will be carried out within the ELITE team (Printed Electronics for Telecom and Energy, see website http://www.xlim.fr/recherche/pole-electronique/rf-elite/elite) at XLIM (Limoges site), which is involved in the production of organic and hybrid devices, their optoelectronic characterization, up to the modeling of their physical properties. The team's know-how is centered on the integration of new materials, the physics of thin films and interfaces, the development of new architectures, their electrical and optical modeling. The team has coordinated many projects in this field and developed strong partnerships with local manufacturers for the development of printing techniques for organic solar cells, for example.
This thesis is part of two projects dedicated to halide perovskites currently conducted by the XLIM ELITE team, involving teams from the Aimé Cotton laboratory (LAC, ENS Cachan) and the Institute of Nanosciences of Lyon (INL) within the framework of the EMIPERO project supported by the French National Research Agency (ANR), and involving on the other hand teams from the Institute of Molecular Sciences (ISM) and the laboratory for the Integration of Materials up to Systems (IMS) from the University of Bordeaux, as part of the STRIPE project funded by the Region Nouvelle Aquitaine. The thesis will take place mainly on the site of the XLIM institute in Limoges and will be carried out in close relationship with the various partners involved, especially through short stays.
Constraints and risks
No constraints / risks other than the risks associated with the handling of common chemicals and solvents for the preparation of thin films and the use of secondary vacuum structures using high-voltage sources (vacuum deposition process).
Applications should be submitted before 21 days after the publication date of the advertisment.
Candidates must hold a master's degree (or be about to validate one) or have a university degree equivalent to a European master (5 years duration). He / she will demonstrate relevant training in semiconductor physics and nanotechnology and will demonstrate an interest in experimental work. Knowledge or past experience in the field of organic optoelectronics (solar cells, OLED, etc.) or halide perovskites will be an advantage, as well as a high level of communication, oral and written (French and English) so to be able to participate in conferences and write articles in scientific publications. In addition, the candidate must be able to work in a team on multidisciplinary projects.
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