Missions

In the context of future tandem photovoltaic cells based on thin-film perovskite layers, low-bandgap bottom sub-cells are undergoing various developments, particularly to extend absorption into the near-infrared (NIR) region, reduce the amount of active materials used, and increase their stability. The "NBG_SolarCells" project aims to develop solar cells that absorb in the NIR by combining optical and material strategies to address the following objectives:
(1) Develop narrow bandgap (Eg) solar cells prepared from solution processes, capable of absorbing photons in the NIR spectrum, with reduced lead (Pb) content, particularly based on Sn-Pb perovskites;
(2) Achieve a fundamental understanding of the material challenges of these photovoltaic systems and propose mitigation approaches to reduce carrier loss channels and prevent absorber degradation;
(3) Unlock their full potential by developing innovative light management approaches based on nanophotonics and plasmonics to enhance solar cell performance.

Activités

The postdoctoral researcher (M/F) will be responsible for developing the perovskite solar cell component of the project within the "Optoelectronics, Photovoltaics and Nanostructures" team at the Paris Chemistry Research Institute (UMR8247). The selected candidate will develop thin-film Pb-Sn perovskites from solution-based processes. Various parameters of the chemical formulation and synthesis will be optimized to obtain high-quality, well-crystallized layers with morphology and thickness suited to the application. These films will be thoroughly characterized using spectrophotometry, photoluminescence measurements, X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and glow discharge optical emission spectroscopy (GD-OES).

The selected candidate will fabricate photovoltaic solar cells using the most promising materials and will evaluate their performance through J-V measurements, while also conducting fundamental studies on device operation. For the most promising compounds, aging tests will be performed on both the thin films and the solar cells.

In a second phase, the researcher will interact with the project partners (ANR project "NBG_SolarCells") to develop optical and photonic strategies aimed at maximizing solar light harvesting and thereby enhancing device performance. The approaches developed will aim to overcome current photocurrent limitations, which are constrained by the short carrier diffusion lengths in these absorbers.

Its work will benefit from the host team's strong expertise in halide perovskite synthesis, high-efficiency solar cell fabrication, and device characterization.

Compétences

We are looking for a researcher with solid experience in photovoltaics, specifically in perovskite-based solar cells. The candidate must have a strong background in materials chemistry and in the synthesis of thin films of semiconductor compounds from solution. They must be proficient in performing syntheses in glove boxes. A thorough mastery of the characterization techniques for materials used in this type of solar cell, as well as photovoltaic cell performance analysis and stability monitoring under standard aging conditions, is essential.

A good level of communication skills, both oral and written (English required), is necessary. We are seeking a postdoctoral researcher who can become fully involved in the project, with a thirst for knowledge, creativity, a degree of independent thinking, and strong motivation. In addition, the candidate will be expected to work in close collaboration and partnership with other members of the ANR consortium (Laboratory of Physics and Study of Materials, ESPCI Paris, and the Institute of Nanotechnology of Lyon).

The application must include: a detailed CV including academic background, previous positions, all publications and scientific presentations; at least two references (individuals who may be contacted by the project advisor); a one-page cover letter; and, if possible, the PhD reviewers' reports.

At the time of recruitment, the candidate must hold a PhD in science. They must also have actively contributed to the writing of at least one article published in a high-impact journal.

Contexte de travail

The recruited person will join the “Optoelectronics, Photovoltaics and Nanostructures” team at the Paris Research Institute of Chemistry (Institut de Recherche de Chimie-Paris, UMR8247). This team develops advanced material synthesis techniques with structural control at the micro- and nanometric scales. These materials are designed to play an active role in devices and improve their efficiency. The combination and assembly of materials are key areas of investigation within the team, with the goal of achieving new or enhanced properties (self-assembled layers, junctions, sensitization, photon management, etc.). The materials prepared are mainly n-type or p-type semiconductors, particularly doped or undoped oxides, as well as halide perovskites. These semiconductors feature tunable bandgaps, finely controlled doping, and are fabricated as thin films, nanostructured layers, or nano-objects.

The synthesis techniques used are mostly low-temperature processes in which chemical precursors are dissolved in solution. We specialize in electrochemistry, spin-coating, spray pyrolysis, and hydrothermal growth. We also work on integrating these layers into high-performance devices. More details about the team's activities can be found on the website: www.pauportegroup.com. The postdoctoral researcher will work under the direct supervision of the team leader, Prof. Thierry Pauporté.

The host laboratory is the Paris Research Institute of Chemistry (Institut de Recherche de Chimie-Paris, UMR8247). IRCP promotes integrated research, from fundamental science to applications, spanning a wide range of chemical disciplines: from molecular and polymer chemistry to energy, materials, and chemical processes. The laboratory comprises 217 members, including 88 permanent staff.