CNRS/GeePs – Internship/PhD – Triple-junction solar cell modeling and development in a Horizon Europe research project F/H


Function:                  Intern/PhD candidate

Contract :                 Internship agreement

Start :                         To be defined

Duration :                  6 months

Lieu de travail :       GeePs – 11 rue Joliot Curie, 91192, Gif-sur-Yvette

Formation :              Master 2/Engineer 3A



The internship will take place in the framework of a collaboration with the UMR-IPVF and the GeePs. The UMR-IPVF is an academic research unit associated with IPVF. GeePS is a research unit (CNRS/Univ. Paris-Saclay/Sorbonne Univ.) specialized in electrical and optoelectronic characterization. The two laboratories work closely together to develop advanced characterization methods in the dedicated program of the IPVF. 

The IPVF – Institut Photovoltaïque d’Île-de-France, an institute for energy transition created in 2013, is a scientific and technical cluster dedicated to the research and development of solar technologies. On its site located in Paris-Saclay, it brings together its own staff, employees of its partners and those of external companies. The IPVF’s ambition is to become one of the world’s leading centers for research, innovation and training in the field of energy transition.

The IPVF’s primary objective is to improve the performance and competitiveness of photovoltaic cells and to develop breakthrough technologies.

Ideally, the intern selected will pursue her/his work with a PhD thesis.



The development of photovoltaic power is a booming area in research and in industry.  The TRIUMPH research project is at the forefront of this, as a part of the €95 billion Horizon Europe research program of the European Union which has started in 2022. TRIUMPH develops new breakthrough triple-junction solar cells going above the Shockley-Queisser efficiency limit and aiming for cell efficiencies above 30%. To achieve this, TRIUMPH will develop high bandgap and middle bandgap solar cells using revolutionary perovskite which are integrated on a silicon low bandgap cell, and in a two-terminal device configuration.

The research position will contribute to theory and experimental development. The work will include developing simulation models of the triple junction device by developing existing numerical models created at GeePs and IPVF. This will consist of modelling key elements such as the optical stack, tunnel junctions between the sub-cells, material properties analysis of novel 2D and 3D perovskite, in order to contribute to triple junction development. The modelling will include modelling of novel perovskite materials,electron and hole transport layers, and buffer layers necessary to device fabrication of high quality materials by partners in TRIUMPH. To do so literature survey for available data, which will be complemented where possible by ab initio data and experimental measurements with techniques such as ellipsometry and compositional analysis of the multilayers in TRIUMPH devices by a range of techniques available within GeePs and IPVF. This will help to get a physical understanding of the novel perovskite absorber and transport layer materials considered for device optimisation. For this work a combination of physical models and datascience will be used for the optimization. The modelling will finally focus on interface dynamics in these complex multilayer structures, identifying transport loss mechanisms and optical loss mechanisms. It will reduce these by optimising materials and device geometries to minimise bulk and interface recombination, and to maximise absorption by suitable tailoring of layer geometries. This will help propose areas for optimization concerning performance and stability. For this the candidate will use the results of advanced characterization to develop and validate the models and analysis.

The research project will include device and materials characterisation. Solar cell devices will be characterised in dark and light conditions with a solar simulator for device level optimisation of cell performance and efficiency potential. It will include evaluation of advanced materials characterisation techniques ranging from luminescence spectra to structural and chemical characterisation techniques such as electron microscopy and photospectroscopy chemical analysis.

This multiscale research project thereby includes a range of theoretical and experimental studies from atomic to device scales. It relies on strong interaction with a range of academic and industrial partners. The project takes place within the framework of a European project won with the main European institutes working on research in the field of photovoltaics. The candidate will work in this high-level environment in contact with the best European institutes on this subject. This will allow the development of triple junction solar cells with a high level of technology readiness level.

A satisfactory internship may lead to a doctoral position.



– Master : Material sciences / Physics, Knowledge in Semiconductor physics, Optics and Imaging techniques

– Prior experience in modeling software and in code or script development, datascience is a plus

– Prior experience in characterisation is a plus

– Strong teamwork skills / Multidisciplinary teamwork

– Proactive and Autonomous




The application can include: cover letter, resume, names and contact details of 2-3 references (name, relation to candidate, e-mail and telephone number), and an electronic copy of your most significant research publications (journal or conference publications).

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