| Context of the research project |
The THz Photonics group at the Institute of Electronics, Microelectronics and Nanotechnologies (IEMN) wishes to recruit a Post-Doctoral student on a fixed-term contract (24 months). The objective of the work will be the design and fabrication of photodetectors operating in the mid-infrared range (5-15m, 20-60THz). The Mid Infrared (MIR) spectrum calls for a wide variety of technologies in the fields of optics and optoelectronics. In this context, the “THz Photonics” team (THz-Photonics-Group publications) – which is proposing this contract – has been developing for several years ultrafast MIR detectors based on III-V semiconductor heterostructures [1,2]. Nowadays these detectors have reached 3dB radiofrequency (RF) bandwidths of ~100 GHz, an unsurpassed performance to date. They consist of arrays of quantum-well photo-detectors coupled to plasmonic antennas [3]. In particular, we were able to demonstrate that their electrical bandwidth is limited by the time needed by the electrons, photo-excited above the potential barriers, to return to the fundamental level of quantum wells. The latter, called capture time, is of the order of a few ps and depends in particular on parameters such as the width of the potential barriers or the energy of the excited state. The RF bandwidth can therefore potentially be modulated, and in particular extended, by modifying the quantum design of the photodetectors. This is one of the aspects that we wish to explore in this project. Another key point is given by the plasmonic antennas, which allow to obtain a collection area of the incident MIR radiation larger than the detectors physical area, thus allowing to reduce significantly the detection noise and therefore increase the sensitivity compared to traditional devices. Presently, our photodetectors exploit patch-type antennas, but we now wish to explore other types of antennas to increase further the radiation collection. Ultimately, the objective of this post-doctoral project is to demonstrate a new generation of photo-detectors in the 8-12μm range. To this end novel devices with an improved performance will be designed, fabricated and characterized, thanks to the design of new types of antennas and quantum structures. In particular we aim for an increase in responsivity by a factor of 2-3 compared to the state of the art, and for an extension of the RF bandwidth up to 200 GHz. The work will take place within the project COMPTERA funded by the French National Research Agency (ANR), in collaboration with Ecole Normale in Paris and CEA-LETI in Grenoble. The goal is to demonstrate the feasibility of MIR detectors with unrivalled performance, for a number of applications such as spectroscopy and gas detection, coherent imaging, telecommunications in space. free, and astrophysics. |
| Candidate profile |
•Motivated post-doctoral fellow, independent, and capable of bringing new ideas. •Good attitude towards team-work. •Solid knowledge of electromagnetics, quantum mechanics and optoelectronic devices. •Know-how in electromagnetic simulation with simulation software such as CST Microwave Studio, HFSS or Lumerical. •Good knowledge of clean-room fabrication techniques. Initial experience in the fabrication of semiconductor devices (MEMS, diodes, photodetectors, transistors, etc.) in a clean-room environment is essential. •Experience in the characterization of optoelectronic devices would be a plus. •Good level of English, spoken and written. •Good writing skills (writing of papers and reports) are highly desired |
| Working environment |
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| To apply : |
Interested candidates are invited to send a CV, motivation letter and contact details of two referees to : Stefano Barbieri stefano.barbieri@iemn.fr Emilien Peytavit More information : here |
Unité d’accueil :
IEMN UMR CNRS 8520
Avenue Poincaré
59652 VILLENEUVE D ASCQ CEDEX
www.iemn.fr
Date de début souhaitée : 1 Janvier 2024
Durée souhaitée : 2 ans
Les candidatures accompagnées d’un CV et de 2 lettres de recommandation doivent être envoyées à :
Stefano Barbieri
stefano.barbieri@iemn.fr
Emilien Peytavit
emilien.peytavit@univ-lille.fr
