Laboratoire d’Études du Rayonnement et de la Matière en Astrophysique et Atmosphères

Accueil > en > Education & Employement > Job Offers > PhD Offers

PhD offer jointly at LERMA, C2N and CNES France - from 2023 to 2026

par Elise Blanchard - publié le , mis à jour le

PhD offer
Jointly at LERMA UMR CNRS 8112, C2N UMR CNRS 9001 and CNES France

"Pushing the Terahertz frontier of GaAs Schottky diodes - New technological developments for sensitive astronomical receivers"

Project context

In spite of the fact, that the strongest emission lines of our Milky Way, such as [NI] (1.46 and 2.46 THz), [CI] (1.9 THz) and [OI] (4.7 THz) etc, lies in the THz/far-infrared region, this region is still largely unexplored due to poor atmospheric transmission and the necessity to observe from space as well as the lack of sensitive receivers. Heterodyne spectroscopy, largely used in astronomy, planetology, Earth science and even in commercial applications, allows the detailed analysis of the incoming signal with excellent spectral resolution.
In a heterodyne receiver the received sky signal is mixed by a mixer with an artificial monochromatic signal created by the local oscillator (LO). These LO and mixer are the heart of a heterodyne receiver and determine its performance. Heterodyne receivers are routinely used up to 350 GHz, but very few mixers and LOs exist at THz frequencies. To open up this observing window it is essential to develop sensitive THz mixers and powerful THz local oscillators..

During the last 15 years, LERMA associated with C2N work together on the design and the realisation of THz mixers and multipliers, based on the GaAs Schottky diodes, in order to build the sensitive THz devices for radioastronomy. Recently, LERMA-C2N developed and fabricated the 300GHz and 600GHz multipliers, as well as the 1.2THz mixer, that are installed on the Submillimeter Wave Instrument (SWI) for the JUICE mission, which will be lanced in 2023 to study Jupiter and its moons. To keep its leading position, LERMA aims to push further the limits of fabrication technology to reach frequencies as high as 5THz.


This experimental thesis has the ambition to develop the process allowing the fabrication of high quality, performant and robust Schottky diodes operating up to 5THz. Several proposals of space missions, that require such THz devices, will be submitted soon in order to answer the call for ESA’s Medium-size class missions (M7) for satellites and the call for NASA’s probes..

The candidate will be co-supervised by two research laboratories (LERMA and C2N) and by CNES. For the process development, she/he will work in the advanced clean room of C2N on state-of-the art equipment for micro- and nano-fabrication. The theoretical study, DC and RF measurements as well as the design and simulation of future 2.7/4.7 THz multipliers will be performed at LERMA. This work will allow the PhD student to acquire a large experience in nano-technology and device fabrication (electron beam lithography, thin metal and dielectric layer deposition, dry etching and other clean room tools), in physics of semi-conductors as well as in DC and RF characterizations of the microwave circuits.


- Required education level : Master or equivalent degree in electrical engineering or physics.
- Duration : 36 months.
- Required background : Physics of solids (semiconductors). Knowledge in nano/microfabrication or in radio wave frequency electronics is welcome.
- Good knowledge of English is expected.

Others informations

Deadline to apply : as soon as possible, submission deadline March 10, 2023

Contact persons : To apply please send your motivation letter, CV, and recommendation letters (optional) to :

Dr. Martina WIEDNER (LERMA, Observatoire de Paris, Paris),

Dr. Lina GATILOVA (LERMA, Observatoire de Paris, Paris),

Dr. Yong JIN (C2N, CNRS, Paris),

All the candidatures are evaluated. However, due to the large number of applications we receive, we will contact only the short-listed candidates.