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PHD RESEARCH PROPOSAL H/F


Vacancy details

General information

Organisation

The French Alternative Energies and Atomic Energy Commission (CEA) is a key player in research, development and innovation in four main areas :
• defence and security,
• nuclear energy (fission and fusion),
• technological research for industry,
• fundamental research in the physical sciences and life sciences.

Drawing on its widely acknowledged expertise, and thanks to its 16000 technicians, engineers, researchers and staff, the CEA actively participates in collaborative projects with a large number of academic and industrial partners.

The CEA is established in ten centers spread throughout France
  

Reference

2021-18378  

Position description

Category

Micro and nano technologies

Contract

Post-doctorat

Job title

PHD RESEARCH PROPOSAL H/F

Subject

We propose to study the impact of quantum well design and composition on the performance of µLEDs. Over the last 10 years, researchers have gained a much better understanding of InGaN quantum wells in large LEDs6. However, the requirements for µLEDs developed for micro-displays applications are different from those for large LEDs used in the field of lighting. For example, in the case of large LEDs, it is possible to get blue quantum wells with a very high Internal Quantum Efficiency (IQE~95%) as for green quantum wells IQE cannot go beyond 40% and for red beyond just a few %. However, for µLED, because of the impact of non-radiative recombination at the sidewalls and possible different diffusion coefficients, it is not clear that the performance ranking will remain the same (or at least not with the same ratio). The optimum design and composition of the active region for the fabrication of blue, green and red µLEDs will likely be different from the optimum design of large LEDs.

Contract duration (months)

36

Job description

The proposed PdD thesis will consist in designing and growing InGaN quantum wells by Metal Organic Chemical Vapor Deposition (MOCVD) varying the Indium composition and the active region design and by characterizing them thoroughly with various spectroscopic technics. We are particularly interested by the variations of IQE and the related carrier diffusion length between different designs of quantum wells. In addition, µLEDs will be realized on selected epi-structures to test the performances of devices made with optimized quantum wells. This last step may or may not be realized directly by the student, as the focus of the PhD should be in priority the design, the growth and, for a large part, the characterization of the InGaN quantum wells in order to identify the best structure to make efficient blue, green and hopefully red µLEDs. For this reason, the PhD candidate will be based at the LCEM (emissive devices laboratory) where part of the electro-optical characterization will take place. The growth and part of the structural characterization will be done at the LMP (materials for photonics laboratory). Both laboratories are part of CEA/LETI (Electronics, Technology and Instrumentation Laboratory) in Grenoble.

Applicant Profile

The candidate must have a solid background in solid-state physics and be interested in technological developments related to innovation. He must also have good reporting capabilities given the multidisciplinarity of the work and the interactions between the different laboratories.

Position location

Site

Grenoble

Job location

France, Auvergne-Rhône-Alpes

Location

Grenoble