Transfer of knowledge to industry
Département des Plateformes Technologiques (LETI)
Laboratoire des Matériaux pour la photonique
01-03-2021
PsD-DRT-21-0035
As part of the Carnot PIRLE project starting in early 2021, we are looking for a candidate for a post-doctoral position of 24 months (12 months renewable) with a specialty in material science. The project consists in developing a relaxed pseudo-substrate based on III-N materials for µLEDs applications, especially for emission in red wavelength. The work will focus on developing an InGaN-based epitaxy MOCVD growth process, on an innovative substrate based on electrochemically anodized and relaxed materials. He (She) will have characterize both the level of relaxation of the re-epitaxied layer and its crystalline quality. These two points will promote the epitaxial regrowth of an effective red LED. The candidate will be part of the team, working on the PIRLE project, will be associated to the work on red LED growth and its optical and electro-optical characterizations.
Département des Plateformes Technologiques (LETI)
Laboratoire
01-01-2021
PsD-DRT-20-0113
UV-C LEDS are to replace Hg based UV-lamps for applications related to air and water sterilization and decontamination , a subject of importance in the present day health context. However, UV-C LEDs, which rely on the use of AlGaN nitride alloy epitaxial layers, are still not efficient enough to be considered as a possible alternative on a large industrial scale. This is so for different reasons, related to the quality of the nitride material and/or to the technology employed for fabricating the diodes. We have created an academic consortium which, around LETI, can address the different issues at stake, in order to develop a true technology stream in this field. One of the issue concerns the structural quality of the epitaxial layers, dislocations being non-radiative defects that kill the internal efficiency of the LED. Within the consortium, we are in charge of developping new and optimized template layers, i.e. the epitaxial layer nucleated on the surface of the sapphire substrate, since an important part of the defects in the LEDs arise from this nucleation layer. To address this point, we will develop new and original methods for the deposition of AlN and AlGaN templates: reactive sputtering, co-sputtering (for alloy templates) and Pulsed laser Deposition (PLD). The layers will be characterized on the Nano-Characterization Platfom of LETI and will be evaluated according to the electro-optical properties of the LEDs structures that will be grown by epitaxy on top of these templates.
