Contract: Internship agreement
Start: Spring 2023
Duration: 6 mois
Location: IPVF, 18 Boulevard Thomas Gobert, 91120 Palaiseau
Education: Master 2
Become an actor of the Energy Transition by joining a team driven by innovation and impact to address today’s most decisive challenges.
IPVF is one of Europe’s leading research, innovation and education organizations whose mission is to accelerate the energy transition through science and technology. Supported by the French State, IPVF is labelled Institute for Energy Transition (ITE).
Bringing together recognized industrial leaders (TotalEnergies, EDF, Air Liquide, Horiba and Riber) and world-renowned academic research teams (CNRS, Ecole Polytechnique), IPVF’ multidisciplinary and international teams conduct research dedicated to clean energy technologies (photovoltaics, green hydrogen, etc.). IPVF has built an ambitious scientific and technological research program, divided into 6 programs and 24 sub-projects, to achieve this objective.
These programs are based on a high-level experimental platform of 8,000 m², located in Paris-Saclay, and comprising more than 100 cutting-edge equipment worth €30M.
The understanding of physio-chemical processes at the interface between two functional materials has always been a critically important domain for our advancement of optoelectronic technologies. Today this scientific domain has become indispensable to solve the most critical challenges about the sustainable and secure energy supply of the future. With silicon-based solar cells close to their theoretical limit for the maximum efficiency, we need to explore the toolkit of materials science to make the photovoltaic module of the future. Thus, moving beyond this current state-of-the-art, the newest generation of solar cells are based on novel absorber materials exhibiting a chemical complexity that reaches far beyond the one of silicon and other traditional semiconductor materials.
Controlling surfaces, interfaces, and grain boundaries of halide perovskite (HaP)-based solar cells (PSC) has become one of the main handles to achieve stable high-efficiency devices. Besides, the HaP material itself induces some complexity within this control of the interface formation since it exhibits volatile organic components, mobile ions, and reactive metal halide species.
We aim to investigate the fundamental physical and chemical properties of HaP thin films (including surface termination, reactivity, and electronic structure), as well as their interfaces with adjacent functional thin films. In this endeavor, we are particularly focused on the analysis of chemical reactions at interfaces by photoemission spectroscopy (PES) methods. For instance, we examined the complexity of the chemical and electronic properties of HaPs over light degradation, chemical passivation, oxide deposition, and dependence on the employed oxide substrate.
Main references: P. Schulz et al. Chem. Rev. 2019, 119, 5, 3349-3417; S. Dunfield et al. Cell Rep. Phys. Sci. 2021, 2, 100520
We set two major objectives for this internship to unveil the dynamic properties of additional passivation layers on the HaP film: 1). Monitoring the evolution of the surface photovoltage, surface potential and band bending as a function of the molecular passivation on defective HaP surfaces. In addition to the lab-based photoemission and X-ray absorption spectroscopy data, we will thus conduct steady-state and time-resolved PES measurements of pristine and passivated HaP films with additional laser excitation from the core level shifts. In this approach, we will also evaluate the electronic properties from the valence band measurements and track changes to the work function, which could indicate further dipole effects induced by the organic molecule. 2). Evaluating the impact of the passivation on the charge carrier profile in the HaP as a function of various substrates. For this purpose, we will explore the chemical and electronic properties of the pristine and passivated HaP layers on two different substrates. For the reference case, the substrate will be a organic hole transport layer, whereas in the other test case, we will deposit the layer stack on top of a NiO hole transport layer, which induces a carrier profile in the HaP and changes the carrier dynamics.
This experiment will accrue a large amount of X-ray absorption and electron spectroscopy data taking into account transient changes in the materials properties. The main task in this internship will be to develop appropriate fitting procedures and correlating large datasets to establish a precise model of the dynamic interface properties in perovskite solar cells. The internship will encompass the use of datascience techniques to evaluate the performance and reliability of emerging solar cells and materials.
– Knowledge in semiconductor physics and/or physical chemistry
– Master : Physics / Materials science / Nanotechnology
– Data treatment and analysis
– Interest in numerical methods
– Teamwork for a mixed experimental and theoretical research approach
– Open to work in a multidisciplinary environment
– Curiosity to push scientific boundaries
The application can include: cover letter, CV, and potentially references (name, relation to candidate, and e-mail).
Documents to be sent to:
Philip Schulz – firstname.lastname@example.org
Jean-Baptiste Puel – email@example.com
Feel free to contact us for more information about our offers.