Missions

This research will be conducted as part of the ANR BIRD project. Often considered undesirable, defects in semiconductors, such as vacancies or impurities, can significantly reduce the performance of optoelectronic devices. These defects can also be functionalized to confer new properties on semiconductors. 2D materials, known for their exceptional properties such as the ability to form Van der Waals heterostructures, are also attracting renewed interest due to the properties of their defects. Specifically, persistent photoconductivity (PPC), a phenomenon in which photo-induced conductivity persists after illumination is turned off, has been observed to last for days at room temperature in certain 2D materials. The IRL GT-CNRS recently demonstrated for the first time that 2D h-BN exhibits significant PPC at room temperature for several years after UV illumination, clearly indicating that h-BN can be permanently converted from an insulator to a conductor. This could pave the way for the use of h-BN in optoelectronics and in particular for deep UV emission.

Activities

The objectives of the BIRD project are therefore as follows - Understand the underlying mechanism of the transition from insulator to conductor in h-BN under UV illumination. This mechanism is still unknown, which hinders its optimization. Identifying the defects that cause PPC will therefore be fundamental to controlling their formation during epitaxy. - To optimize the giant PPC effect and use it effectively as a new doping method. Understanding the physics underlying the origin of giant PPC in h-BN is a prerequisite for achieving this. - Demonstrate the creation of h-BN homo-junctions using the photoinduced doping process. The integration of BAlN/BN quantum wells would then be the next step towards highly efficient DUV LEDs.

Skills

In order to achieve these objectives, the researcher engeneer will work more specifically on the microfabrication of basic components, their doping by illumination, the fabrication of advanced components by detachment and transfer, and finally their characterization and analysis (SEM, I(V,t,T), etc.).

Work Context

The position will be assigned to IRL 2958 GT-CNRS, a joint laboratory between the Georgia Institute of Technology and the CNRS. This research will be conducted within the context of IRL 2958 GT-CNRS, an international joint laboratory between the Georgia Institute of Technology and the CNRS, under the supervision of Prof. Jean Paul SALVESTRINI, a specialist in semiconductor component physics and microfabrication. Like any research project, this project is a collaboration with a group of national partners from different fields and will therefore require a certain amount of collaborative work and communication.

The position is located in a sector under the protection of scientific and technical potential (PPST), and therefore requires, in accordance with the regulations, that your arrival is authorized by the competent authority of the MESR.

Constraints and risks

Working in a bilingual environment The position is in a sector covered by the protection of scientific and technical potential (PPST) program, and therefore, in accordance with regulations, requires that your arrival be authorized by the competent authority at the MESR.