Towards sustainable metallization and interconnection for multi-TW photovoltaics

To keep the Earth’s average temperature rise below 1.5˚C compared to pre-industrial levels, our world needs to rapidly transition to a 100% renewable energy system. Solar photovoltaics (PV) will be playing a major role, as it is now the cheapest source of electricity. The estimated needed global PV generating capacity is about 70 TW by 2050, which requires to quickly grow the production capacity from 220 GW/year in 2022 to about 3 TW/year! One of the major challenges for sustainable PV manufacturing is the limited availability of raw materials such as silver (Ag), indium (In), and bismuth (Bi). Ag, for example, is used throughout the PV industry for the metallization of solar cells. If nothing changes, at the 1 TW/year level of production, the PV industry will use 100% of the global supply of Ag. With new higher-efficiency technologies such as TOPCon, heterojunction or tandems, relying even more on these limiting materials, the roadmap for upscaling is now calling for transversal solutions, taking into account not only technological limitations but also environmental and economical ones. The focus of the Ph.D. candidate will be on exploring novel sustainable metallization and interconnection materials and methods for enabling a TW PV deployment in a circular economy, taking into consideration the multiple and interdependent facets of this challenge. Techno-economic and life cycle assessments in collaboration with EnergyVille partners will guide comparative studies and eventual selection.

The Ph.D. candidate will join imec’s PV technology group performing world-class research on advanced thin-film and wafer-based technologies at our state-of-the-art research facilities located at the Energyville Campus in Genk. The research will be very versatile, as it will encompass both exploring broad metallization options (transversal literature reviews, modelling) and developing high-performance advanced metallization/interconnection schemes with no (or limited) usage of Ag, In or Bi (including using advanced characterization and technical simulation tools). On top of this, the Ph.D. candidate will have the possibility to work with imec’s PV experts to improve the eco-design of PV cells and modules. Finally, he/she will also have the unique opportunity to work on those different topics with our industrial partners in multiple bilateral/funded European projects.

Illustration source: Zhang et al. in Energy and the Environmental Science 2021, https://doi.org/10.1039/D1EE01814K