PhD position - Study of the persistence in IR MCT imaging retina for earth observation from space

OPPORTUNITY DETAILS

Total reward

0 $

State University

CEA Tech

Area

Western Europe

Host Country

France

Deadline

31 Oct 2021

Study level

Doctoral Degree

Opportunity type

PhD

Specialities

Engineering , Physics

Opportunity funding

Not funding

Eligible Countries

This opportunity is destined for all countries

Eligible Region

All Regions

SL-DRT-21-0855

RESEARCH FIELD

Photonics, Imaging and displays

ABSTRACT

IR detection is a major stake for ongoing and future space science missions studying the atmosphere chemistry (for instance MicroCarb mission dealing with the measurement atmosphere CO2 concentration) and more generally for science imaging and sensing (for instance the ARIEL mission aiming at studying exoplanet atmospheres).IR detector is a major performance driver for such instruments. The most widely used technology relies on a sensitive layer made of HgCdTe, a narrow gap semiconductor, suitable for IR photon absorption. This sensitive layer is then hybridized onto a silicon read out integrated circuit (ROIC) for multiplexing and signal conditioning. This particular technology has been developed at CEA LETI then transferred to Lynred for qualification and production.The very high level of measurement precision of science missions requires an in depth study of all sources of detection performance degradation. Among various biases is the persistence phenomena: like the human eye looking at the sun, ghosts of previous images are sometime polluting detected images, thus degrading the instrument performance.This effect is most of the time attributed to the sensitive layer (often associated to charge trapping-detrapping phenomenon) and is difficult to calibrate. Ideally, we look for a way to suppress or at least minimize this effect, playing with fabrication parameters. This requires an important work to improve our understanding of the physical phenomenon involved in persistence.Within previous developments with CNES, LETI has built a measurement bench suitable for such fine characterisations. This work intend to study this effect on identification detectors, with regard to different detector fabrication variations. A second step will be to identify the most efficient technological solutions in collaboration with Lynred Company producing such detectors. Last but not the least the validation of the proposed solution shall be performed.