Optimised/Alternative Silicon Growth Technologies (from either liquid or gaseous phase) for PV Applications (EUPI-PV Partnership)

Expected Outcome:The majority of commercially available photovoltaic (PV) solar cells produced worldwide are made of crystalline silicon. Material quality, process technologies, and solar cell architectures have improved significantly in recent decades, and solar cell efficiencies are now approaching 27%, thus close to the theoretical limit. However, challenges remain in several aspects, such as increasing the production yield, stability, reliability, cost, and sustainability.

The ingot and wafering production steps are power intensive and produce recyclable waste in the form of kerf slurry – the residue ingot material from between the sliced wafers. These production steps are highly concentrated in China.

Project results are expected to contribute to all of the following expected outcomes:

• A European economic base which is stronger, more resilient, competitive, and fit for the green and digital transitions, by reducing environmental impact and strategic dependencies for critical raw materials and components;
• Scaling-up solar PV manufacturing capacity in Europe for an accelerated solar PV deployment, supporting Europe’s decarbonisation targets;
• Reduced energy and material consumption and lower carbon and environmental footprint for crystalline silicon PV products along their lifecycle;
• The execution of the solar energy joint research and innovation agenda[1].

Scope:Due to their efficiency and durability, crystalline silicon wafers are by far the most common absorber material used in the production of solar cells and modules today. These wafers are primarily made using either a directional solidification that produces large-grained multi-crystalline (mc-Si) wafers with a greater defect density (and therefore almost out of production) or a solar-optimised Czochralski (Cz) growing method that produces crystalline silicon with low defect density (c-Si). In addition, “kerfless” silicon wafers can be grown directly either from molten silicon or from gaseous epitaxial deposition on a low-cost substrate at high temperature. To facilitate continued and rapid proliferation of Si photovoltaics, realizing new, more efficient and less energy and material intensive processes for silicon feedstock, ingots and wafers is sought. Therefore, proposals are expected to address at least one of the following challenges:

• Demonstrate alternative, efficient, and scalable (towards gigawatt capacity) processes or methods and equipment to grow silicon ingots and wafers from either liquid or gaseous phase at lower cost (with lower energy and material requirements) and high-quality compared to standard processes and possibly avoid the wafering step;
• Optimise standard processes and equipment for defect, impurities and structure loss minimisation, high-quality ingots with large diameters (for larger wafers) that allow for higher level of automation and kerf recycling and/or use of recycled silicon from waste solar modules and reduced energy use; optimise wafering.

Proposals are expected to involve multidisciplinary consortia including at least one silicon ingot and wafer manufacturer.

Whenever the expected exploitation of project results entails developing, creating, manufacturing and marketing a product or process, or in creating and providing a service, the plan for the exploitation and dissemination of results must include a strategy for such exploitation. The exploitation plan should include preliminary plans for scalability, commercialisation, and deployment (feasibility study, business plan) indicating the possible funding sources to be potentially used (in particular the Innovation Fund).

This topic implements the co-programmed European Partnership for Innovation in Photovoltaics (EUPI-PV). As such, projects resulting from this topic will be expected to report on the results to the European Partnership for Innovation in Photovoltaics (EUPI-PV) in support of the monitoring of its KPIs.

[1] Commission Staff Working Document "Solar energy joint research and innovation agenda with Member States in the context of the European Research Area (ERA)"