COST-COMPETITIVE SOLAR CELL DEVELOPMENT - EXPRO+

Objective: To develop a cost-competitive solar cell either III-V-based or silicon-based for LEO satellite constellations.Description:The satellite industry is undergoing a major shift from traditional geostationary (GEO) platforms to large-scale lowEarth orbit (LEO) constellations. In this new landscape, solar cell requirements are increasingly driven by the needfor scalability, cost competitiveness, and radiation hardness tailored to the LEO environment. III-V multi-junctionsolar cells remain the benchmark for efficiency and space reliability, but their high cost and manufacturingcomplexity limit their suitability for mass production. In contrast, silicon-based solar cells, widely used in terrestrialsolar arrays, offer a more scalable and cost-efficient option, though they are not optimized for the spaceenvironment and typically have lower radiation resistance. Future development of III-V cells should focus onreducing complexity and cost. For silicon technologies, the priority is improving tolerance to radiation-induceddegradation, which is generally more severe than in III-V cells.Within this activity, it is foreseen to develop one solar cell technology that can support the LEO constellations inview of cost competitiveness and production capability. Technology options for this activity are either III-V-basedor silicon-based, with the following specific objectives: Option 1 - III-V-based technology development, to reduce production costs by up to 50% and doublemanufacturing throughput to meet large-scale deployment needs: there is substantial potential to reduce costsand increase manufacturing throughput by optimizing existing processes or implementing new ones. Potentialstrategies include increasing epitaxial growth rates, integrating terrestrial PV techniques (e.g., screen-printingfor contactmetallization), and replacing photolithography steps with more cost-effective alternatives.For this option, the activity encompasses the following tasks:o Develop an optimized manufacturing route for III-V solar cells, incorporating both improvements tocurrentprocesses and introduction of new techniques.o Fabricate solar cell samples using the newly developed manufacturing process.o Conduct an engineering test campaign to evaluate and validate the electrical and mechanicalperformance of the produced cells.This development stream complements developments performed in the following activity: T703-900EP - HighEfficient Cost-Effective Solar Cells. Option 2 - Silicon-based technology development, with the aim to achieve 21% efficiency at beginning-of-life(BOL) and 18% at end-of-life (EOL) and to improve reliability in the LEO space environment. The developmentactivity will focus on both design innovation and process optimization, aiming to enhance radiation toleranceand thermal cycling robustness while achieving the required beginning-of-life (BOL) and end-of-life (EOL)efficiency targets. For this option, the activity encompasses the following tasks:o Implement cell design optimizations already identified for existing silicon solar cell concepts toimprove radiation resistance to meet the 21% BOL and 18% EOL efficiency targets.o Investigate alternative metallization methods, anti-reflective coatings (ARCs), and interconnectiontechniques to improve thermal cycling robustness.o Explore compatibility of silicon structures with potential self-annealing properties to mitigate radiationinduceddegradation with industrial manufacturing framework.o Validate the final solar cell design through an engineering test campaign.This development stream complements developments performed in the following activity: Spin-indevelopment of terrestrial solar cell technology for constellation applications (ARTES AT 4F.175).