CNRS Postdoc – Advanced spectral analysis of hot carriers photoluminescence for solar cell applications


Function: Postdoctoral researcher

Contract Type: CDD

Starting Date: ASAP

Working Place: UMR IPVF, 18 boulevard Thomas Gobert, 91120 Palaiseau (FRANCE)

Duration: 18 months

Education: PhD in Physics or related (optical setup, spectroscopy, data analysis…)



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).





This post doc takes place in the framework of the ICEMAN ANR project (Improvement of photovoltaic Conversion Efficiency by acting on thermalization MecANisms) which gathers 5 labs (IPVF, C2N, LPCNO, IN2MP and FOTON) to investigate Hot Carriers Solar Cells (HCSC).
When high energy photons are absorbed in a material, carriers are photo-generated with a large of kinetic energy above the band edge. In most cases, this excess in energy is quickly dissipated, and carriers form a quasi-thermal distribution at the lattice temperature. However, in some well-tailored devices, it is possible to slow down this relaxation such that carriers form a “hot” distribution instead. Hot  carriers have a large span of  consequences for the device operation, some negative (hot carriers induced degradation in silicon transistors), some positive (pathway to very high efficiency of solar energy conversion, advanced cooling applications for ICT). Applied to energy conversion, hot carriers open a route towards high efficiency thermoelectrics by limiting losses due to lattice thermal conductivity, and to high efficiency solar cells by combining photovoltaic (PV) and thermoelectric effects in a single device. Hot carrier solar cells are one of the candidates for the realization of ultimate conversion efficiencies in PV.
The ICEMAN project aims at producing a proof of concept for a full HCSC. Our team at IPVF has developed a strong expertise is theoptical characterization of hot carriers with spectral + spatial resolution (hyperspectral) and spectral + temporal resolution (streak camera). Within the consortium, our contribution is therefore to characterize and understand the properties and dynamics of photogenerated hot carriers through  photoluminescence.




This post doc project will address two objectives:

1. Perform extensive optical characterization of HCSC devices developed for the ICEMAN project. This task will require experimental acquisition, optical modeling and data analysis. The aim of these studies is to assess the performance of the device, and to provide guidance for the design and the improvement of the next batch of samples.

2. Develop further strategies to investigate and understand the dynamics of hot carriers. Our team is currently investigating several questions, notably to bridge the gap between steady state and time resolved analysis; and to clarify the thermoelectric properties governing hot carriers transport in HCSC (Seebeck effect). The exact scope of this task will be defined according to the profile, expertise and interest of the candidate.

This work will be carried in collaboration with a PhD student (T. Vezin) and supervised by two senior researchers (D. Suchet & JF Guillemoles). A good knowledge of optics experiment and analysis (spectroscopy, microscopy) is required, but the candidate is not expected to have previous experience in the field of solar cells.

Recent publications :
– H. Esmaielpour et al., “Impact of excitation energy on hot carrier properties in InGaAs MQW structure”, (accepted in Prog. in Photovoltaics, 2022).
– H. Esmaielpour, et al. ,”Hot carrier relaxation and inhibited thermalization in superlattice heterostructures: the potential for phonon management”, Applied Physics Letter (Featured Article) 118.21, 213902 (2021).
– M. Giteau, et al., “Identification of separate surface and volume thermalization mechanisms in hot-carrier solar cells”, Journal of Applied Physics 128.19 193102 (2020).
– D.T. Nguyen et al, “Quantitative experimental assessment of hot carrier-enhanced solar cells at room temperature” Nature Energy 3, pages236–242 (2018)




We are looking for a candidate with expertise in optics (optical setup, spectroscopy, data analysis…). A bit of semi conductor modeling may help, but is not mandatory. No prior knowledge of solar cells is required – and it can be a good opportunity for candidates with a background in fundamental physics to acquire an experience in the field of photovoltaics.




Interested applicants should submit a CV and a cover letter to:

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