Internship: Ageing Processes of CIGS Cells for Solar-to-Fuel Conversion

Copper Indium Gallium Selenide (CIGS) is a promising thin-film photovoltaic technology, renowned for its high efficiency, stability, and low manufacturing costs. With efficiencies recently reaching up to 23.6%, CIGS stands out as one of the top-performing solar absorbers. Beyond electricity generation, CIGS solar cells hold the potential for solar-to-fuel conversion. This is achieved by integrating them with multifunctional oxide layers and catalysts to enable solar-driven catalytic CO2 conversion.

CIGS-based solar cells, when used for solar-to-fuel conversion, are exposed to complex chemical conditions that can affect their long-term performance. A key objective is to identify the degradation processes occurring in the different layers of the cell—absorber, buffer, and contacts in combination with catalysts— under light exposure and electrical stress. To address this, a comprehensive and detailed characterization, combining chemical and physical analyses, is essential to fully understand the degradation kinetics and transformations occurring in the various layers

IPVF optical characterization laboratory is at the forefront of the development of advanced characterization methods for solar cells with solid expertise in hyperspectral luminescence and Time-Resolved Fluorescence Imaging (TR-FLIM) as well as in the advanced characterization of emerging materials and innovative cell architectures.

This six-month internship focuses on developing an advanced in-situ photoluminescence setup to investigate degradation processes in CIGS absorbers for solar-to-fuel applications. The project aims to study the impact of electrolytes and electrochemical reactions on the optoelectronic properties of CIGS absorbers by testing various compositions and functionalized oxides.

Steady-state luminescence imaging techniques will be employed to monitor the evolution of key material properties, such as band gap and quasi-Fermi level splitting (QFLS), during electrochemical reactions over varying durations. This approach will help establish a direct link between electrochemical reactions and material degradation, shedding light on reaction kinetics and identifying the most stable and promising systems. Ultimately, the findings will contribute to developing more efficient solar-to-fuel technologies.

This internship provides an opportunity to work at the intersection of materials science and renewable energy research.

Request skills:
– Semiconductor physics and/or chemistry/electrochemistry
– Optics
– Data Processing and Statistics
– Curious and challenge-driven
– Autonomous
– English B1

Supervisors: Negar Naghavi and Stefania Cacovich
Emails: negar.naghavi@chimieparistech.psl.eu and stefania.cacovich@cnrs.fr