CNRS Postdoc – Passivating and transparent selective contacts for ultra thin Cu(In,Ga)Se2 and Cu(In,Ga)S2 on Silicon solar cells

Function: Postdoctoral researcher Contract Type: CDD Starting Date: ASAP Working Place: Palaiseau, France (technology cluster, Paris area) Duration: 36 months Education: PhD in Materials Science, Physics or related  


Become an actor of the Energy Transition by joining a team driven by innovation and impact to address today’s most decisive challenges. IPVF – Institut Photovoltaïque d’Île-de-France, is a global Research, Innovation and Education center, which mission is to accelerate energy transition through science & technology. Gathering industrial PV leaders (EDF, TotalEnergies, Air Liquide, Horiba and Riber) and world-renowned academic research organizations (CNRS, Ecole Polytechnique), multi-disciplinary and international IPVF teams conduct research for clean energy technologies. Supported by the French State, IPVF is labelled Institute for Energy Transition (ITE).   IPVF at a glance: • An ambitious Scientific and Technological Program (6 programs divided in 24 work packages): from tandem solar cell technologies to economy & market assessment, state-of-the art characterization, photocatalysis and breakthrough concepts. • State-of-the-art technological platform (8,000m²): more than 100 cutting-edge equipments worth €30M, located in cleanrooms (advanced characterization, materials deposition, prototypes for fabrication, modelling…). • High-standard Education program (M.S. and PhD students).  


CuInxGa(1-x)Se2 (CIGSe) solar cells are expected to reach a global market of $8.5 billion by 2024 and this goal is supported by a dynamical joint research activity of industry and academy (White Paper for CIGS). The current state of the art cell by Solar Frontier (23.35%, 2019) results from years of optimization of the CdS/CIGS heterojunction, the absorber grain structure and Ga-grading, and grain boundary passivation by alkali metals. Relatively minor attention was dedicated to replace the low-performing not selective molybdenum back contact with a more suited one. In the ANR project PASTEL (“Passivating and transparent selective contact for Cu(In,Ga)(Se,S)2 solar cells”), we will investigate new passivating and transparent selective hole contacts for CIGSe solar cells, making this technology compatible with highly reflective back mirrors, while preserving the “substrate configuration” production lines used in industry [1]. Even more challenging, we wish to implement this technology on nanostructured back mirrors enhancing absorption by light trapping [2], and based on low-cost nanofabrication technologies [3]. The goal of the project is to fabricate high efficiency ultra-thin CIGS solar cells with absorber thickness of less than 500 nm. This 5-fold reduction in the absorber thickness as compared to commercial solar cells will translate in 5-fold increase of solar cell fabrication throughput. In the PASTEL project we will also investigate the use of passivating and transparent selective holes contacts adapted to wide-bandgap sulphide absorbers Cu(In,Ga)S2 [4], as a proof of concept for chalcogenide on silicon tandem solar cells.     The partners of the project are C2N-CNRS, IPVF, SVI-CNRS-Saint-Gobain and IMN.   [1] Gouillart, Cattoni et al., Interface engineering of ultrathin Cu(In,Ga)Se2 solar cells on reflective back contacts, PIP 29, 212 (2021) [2] Massiot, Cattoni, Collin, Progress and prospects for ultrathin solar cells, Nature Energy 5, 959 (2020) [3] Hung-Ling, Cattoni et al., A 19.9%-efficient ultrathin solar cell based on a 205-nm-thick GaAs absorber and a silver nanostructured back mirror, Nature Energy volume 4, 761 (2019) [4] Crossay et al., Pure sulfide wide gap CIGS on silicon for tandem applications by exploring versatile coevaporation of metallic films and sulfur annealing, 2021 IEEE 48th Photovoltaic Specialists Conference (PVSC).    


The post-doc will work at C2N, IPVF and SVI (all partners in the Paris area) and benefit from a multidisciplinary environment involving several renowed teams. The work will be focused on the development and the optimization of the passivating and transparent selective contact (primarily by magnetron sputtering and ALD), its integration over a (nanostructured) silver mirror and the fabrication of the complete CIGS solar cell and its optoelectronic characterization. If standard deposition of the CIGS(e) absorber will be carried out at IMN in Nantes, the post-doc may be involved in the depostion of CIGS at IPVF for test samples used to study the passivating properties of the contact by photo- and cathodo-luminescence.      


The ideal candidate will have a PhD in material science, physics or related. Previous experience on magnetron sputtering deposition, CIGS co-evaporation, nanofabrication, solar cell fabrication and characterization are desirable. The position will start immediately for a duration of 36 months.    


Interested applicants should submit a CV, a motivation letter and recommendation letters or contact information of former supervisors to:,, Applications will be reviewed as received until the position is filled.

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