General information
Offer title : Post-doctorat (M/F) prématuration CNRS: Fabrication and engineering of GaAs/Si tandem solar cells using plasma based CVD process (H/F)
Reference : UMR7647-KAROUA-001
Number of position : 1
Workplace : PALAISEAU
Date of publication : 01 October 2025
Type of Contract : Researcher in FTC
Contract Period : 12 months
Expected date of employment : 1 December 2025
Proportion of work : Full Time
Remuneration : €3,081.33 – €4,291.70 gross monthly salary, depending on experience
Desired level of education : Doctorate
Experience required : 1 to 4 years
Section(s) CN : 10 - Fluid and reactive environments: transport, transfer, transformation processes
Missions
We are seeking a highly motivated postdoctoral researcher to join our team at LPICM, a joint unit between CNRS and Ecole Polytechnique, in the frame of a 'prematuration' program which aims at exploring original research that can transform into a startup project. This project focuses on developing high-efficiency III-V/Si tandem solar cells by integrating gallium arsenide (GaAs) layers on low-cost, abundant crystalline silicon (c-Si) substrates.
This project aims to address these challenges by exploring the epitaxial growth of thin GaAs layers, using a low-cost and original epitaxial technique, on c-Si substrates using a particular intermediate buffer layer to accommodate lattice mismatch while enabling the active use of Si as a bottom cell.
Activities
The applicant will be involved in the deposition and optimization of the GaAs, its doping, passivation/contact aspects along with interfaces engineering. Ultimately, we expect the fabrication of a first tandem GaAs/Si solar cell demonstrator, offering a viable alternative to current single-junction silicon PV technology with potential for superior performance.
Skills
● A relevant PhD degree in semiconductor physics, material sciences, or similar.
● Hands-on experience with III-V semiconductor deposition processes (e.g. MOCVD, MBE …), advanced semiconductor characterizations (structural, optical and electrical) and/or interface passivation approaches.
● Experience in III-V solar cells design and fabrication.
● Knowledge of semiconductor device modeling is desirable but not required.
● You are a team player with a high level of motivation, self-initiative and independence, excellence and flexibility to work and deliver results.
● Interest in participating to the creation of a deeptech startup
Work Context
This project focuses on developing high-efficiency III-V/Si tandem solar cells by integrating gallium arsenide (GaAs) layers on low-cost, abundant crystalline silicon (c-Si) substrates.
Current high-performance GaAs-based solar cells are typically fabricated via epitaxial growth on lattice-matched substrates such as c-GaAs or c-Ge. However, the high cost of the conventional growth techniques as well as these substrates are significant barriers to large-scale deployment of III-V solar technologies.
Constraints and risks
None
Additional Information
--