STAGE – CNRS – Passivation Layer Design for Perovskite Solar Cell Technologies

28/10/2023

Function :                Intern

Contract :               CNRS internship agreement

Starting date:        February/march 2024

Duration:                 6 months

Workplace:             IPVF – 18 boulevard Thomas Gobert, 91120 Palaiseau

Education:              Master 2

 

IPVF – Institut Photovoltaïque d’Île-de-France

IPVF is a scientific and technical pole dedicated to the research and development of solar technologies. It permanently hosts its own staff, as well as the employees of its partners and external companies. IPVF aims to become one of the world’s leading centers for research, innovation, and training in the field of energy transition.
IPVF primary objective is to improve the performance and competitiveness of photovoltaic cells and develop breakthrough technologies by relying on four levers:

• Ambitious research program.
• The hosting of more than 200 researchers and their laboratories on its Paris-Saclay site.
• A state-of-the-art technology platform (8,000 m²) open to the photovoltaic industry actors, with more than 100 state-of-the-art equipment units located in clean rooms.
• A training program mainly based on a master’s degree, the supervision of PhD students, and continuing education.

 

Brief history:

The IPVF was founded in 2013 on the initiative of the French government, EDF, TotalEnergies, Air Liquide, CNRS, Ecole Polytechnique, Horiba and Riber. Bringing together more than 150 researchers, our 8,000 square meter Paris-Saclay platform is a unique platform for all types of deeptech research and innovation.

The IPVF aims to remain:
• A world leader in photovoltaic-related R&D. By federating the best French teams in the field of research, innovation and industrial production, in partnership with major international institutes, particularly in Europe,
• A leader in the development of photovoltaic technology bricks in line with market trends,
• A reference in sending the most promising R&D concepts to the industry.

 

 

CONTEXT

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 the 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 metal halide perovskite (MHP)-based solar cells (PSC) has become one of the main handles to achieve stable high-efficiency devices. Besides, the perovskite 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.1 Furthermore, since MHPs denote a class of new absorber materials with tunable wide optical band gap, they offer the opportunity to implement advanced concepts like tandem solar cell architectures to increase power conversion efficiency in a scalable and cost-effective manner.2 However, tandem devices feature an even larger complexity and amount of interfaces that put further constraints on the design rule for the films adjacent to the perovskite, resulting in the need to precisely control the interlayers between perovskite and the other functional cell components layer for maximum performance and stability.3
We aim to investigate the fundamental physical and chemical properties of MHP 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 MHPs over light degradation, chemical passivation, oxide deposition, and dependence on the employed oxide substrate.

References:
[1] P. Schulz et al. Chem. Rev. 2019, 119, 5, 3349-3417; S. Dunfield et al. Cell Rep. Phys. Sci. 2021, 2, 100520
[2] M. Jost et al. Adv. Energy Mater.2020, 10, 1904102
[3] J. Christians, P. Schulz et al. Nature Energy 2018, 3, 68-74

 

MAIN OBJECTIVES

The principal objective of this internship is the development and optimization of the passivation layer in the p-i-n structure of perovskite solar cells. Such a passivation layer is comprised of a molecular monolayer between the perovskite active layer and the charge transport film underneath, which allows for an improved extraction of charges while reducing undesirable recombination.

Thus, the focus of this five-to-six-month internship position will be on phosphonic acid carbazole (PACz-) based passivation layer, which is currently integrated into the baseline inverted perovskite solar cell fabrication line at IPVF. Despite its role in enhancing the efficiency and stability of solar cells, application of the films results in non-ideal wettability. The hydrophobicity of the newly formed surface then influences the deposition of the perovskite top layer grown by wet deposition techniques, such as spin-coating or slot-die coating, and eventually leads to the formation of a non-uniform absorber layer. In this internship, the candidate will specifically work on optimizing the passivation layer by introducing a tailor-made mixture of PACz molecules as an additive. These selected additives have demonstrated improved wettability and higher ionization energy, making them promising candidates to complement the existing passivation layer. Different concentrations of the various additives will be mixed into the baseline passivation layer to track how they change the performance parameters and stability of the perovskite solar cell.
The intern will be trained on how to fabricate and characterize thin films as well as perovskite solar cells. The intern will have the opportunity to discuss her/his results, progress, and challenges in a bi-monthly meeting with the corresponding supervisors of the internship offer. The favorable results obtained by the intern will be implemented into to standard process to fabricate large-scale perovskite solar cells and Tandem solar cells.

 

PROFILE

Knowledge

– Knowledge in semiconductor physics and/or physical chemistry
– Master : Physics / Chemistry / Materials science / Nanotechnology
– Analytical skills and knowledge of characterization techniques
– Ideally experience in thin-film fabrication and clean room environments

 

Self-management skills

– Teamwork for a mixed experimental and theoretical research approach
– Open to work in a multidisciplinary environment
– Curiosity to push scientific boundaries

 

CONTACT

The application can include: cover letter, CV, and potentially references (name, relation to candidate, and e-mail)

Documents to be sent to:

Estelle Cariou – estelle.cariou@ipvf.fr

Javid Hajhemati – javid.hajhemati@cnrs.fr

Philip Schulz – philip.schulz@cnrs.fr

Need a direct line?

Feel free to contact us for more information about our offers.

  • +33(0)1 69 86 58 60
  • contact@ipvf.fr
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