Key takeaways:
SHINE PV brings together European research and industry partners to develop alternatives to standard TOPCon and HJT manufacturing processes
New metallization approaches, such as dispensing and plating, aim to reduce silver usage and improve process efficiency
Interconnection and post-processing innovations focus on enabling high-throughput manufacturing and improving cell performance
There has been a steady push to increase domestic manufacturing and technological capabilities in Europe to reduce dependence on foreign supply chains. There have already been some achievements in these areas as a result of EU projects, mainly through consortia between several R&D institutes and industry associations. One such project under a consortium is SHINE PV, which started in January 2025.
The collaborators under this project comprise research teams from academia, R&D institutes, and industrial equipment and material providers. SHINE PV is funded by the European Commission, and its goal is to develop alternative technological routes for the mainstream production of TOPCon and heterojunction (HJT) technologies.
The main focus areas of this project are metallization, post-processing of cells, and module-level interconnection. As part of the project, different work packages (WPs) have been identified and distributed among the partners as per their competence and experience. Fraunhofer ISE, CEA-INES, imec, Applied Materials, Engisoft, and TNO are responsible for WPs 1 through 7, with other participants from academia and the R&D community also involved to support the leaders of these individual WPs.
For metallization, SHINE PV participants are exploring alternative techniques to mainstream screen printing, namely parallel dispensing of metal paste and plating. They conducted initial simulations, followed by the development of equipment to fulfill the dispensing method, with the dispensing kit developed by HighLine (HL) and Fraunhofer ISE. The project has also addressed key issues related to head leaks and hardware/software integration in high-volume manufacturing (HVM) tools.
For plating, researchers are working on Ni-Cu-Ag or Ni-Cu-Sn processes, which have shown promising results. Using the plating technique with silver-coated copper particles as a seed layer, they achieved a silver consumption of about 1 mg/W, as we discuss in Ni/Cu/Ag Plating Reduces Silver Use In TOPCon Cells. Laser sintering is another approach used after paste printing, especially for copper pastes, as it minimizes thermal impact on a-Si passivation in HJT and avoids Cu diffusion in TOPCon cells.
Post-processing light soaking (LS) or edge repassivation (ERP) methods were also demonstrated on the sliced cells. Both LS and ERP individually contributed to efficiency gains, with LS averaging about a 0.5% increase. It was also observed that 80% of the pre-laser-cut cell properties were recovered using ERP, and this was demonstrated for the shingle edges of HJT cells. The next steps in post-processing involve integrating high-throughput tools, such as plasma-enhanced atomic layer deposition (PE-ALD), reliability testing, and evaluating CapEx impact on HVM tools.
On the interconnection side, researchers explored the TWILL method, which involves multiple-wire interconnection, with copper wires embedded in polymeric carrier foils. The metal interconnection actually occurs during lamination, eliminating the need for a stringing step. At this stage, teams from imec, IPTE, and ARK are evaluating reliability using different combinations of encapsulants and cells. The idea is to scale this interconnection to process M10- to G12-sized half-cut cells. Shingling is another approach to interconnection, achieved using electrically conductive adhesives (ECAs) to form interconnections between cells by slight overlapping. The main focus areas of this interconnection approach are to reduce silver content in ECA, reduce the overlap region, and improve handling of thin wafers.
WPs related to equipment development for these alternative technology routes, integration into production lines, life cycle assessment (LCA), and management are also being explored as part of this project, and the solutions in these directions can be found in Sustainable, High-Throughput, Industry-Ready, Next-Generation Technology For European Manufacturing Leadership In Photovoltaics (Shine PV).