Towards Terawatt Production of c-Si Solar Photovoltaics

TERASUN aims to develop technologies making c-Si PV solar cells more efficient and cost-effective.

The project will innovate on Si heterojunction (SHJ) solar cell technology, currently holding the c-Si power conversion efficiency record of 26.81% for single junction c-Si solar cells.

By targeting higher efficiencies and lower costs, TERASUN paves the way for mass production of improved SHJ solar cells.

TERASUN will develop: (i) nanophotonic structures on module cover glass to minimise reflection (maximise absorption) and improve anti-soiling properties and improving the overall performance of the module, which will allow for reduced silicon consumption and higher efficiencies; (ii) innovative texturisation, including micro- and nanostructures for optimal light-trapping to enable the use ultrathin crystalline Si solar cells; (iii) novel heterojunction contacts based on metal-oxide layers implemented in interdigitated back contact (IBC) SHJ solar cells for very high efficiencies, and low-cost surface passivation for advanced surface structures; (iv) low-cost metallisation, replacing silver with copper to move towards a technology ready for terawatt production scale; and (v) direct bandgap architectures for implementation in IBC SHJ solar cells.

These developments will help with approaching the fundamental limit of 29.43% on cell level and reducing cell-to-module losses for optimised energy yield. The strategic choice of materials (Cu, Al-doped Zn oxide, Sn oxide) will reduce the costs and supply chain risks.

Environmental, economic and performance data associated with the developments will be gathered, evaluated and used to develop an algorithm based on multi-disciplinary design optimisation to create the TERASUN decision support tool (DST).

The DST will provide stakeholders from industry and policymakers with: (i) recommendations related to the most promising technologies and (ii) a clear roadmap for the technologies developed in TERASUN towards TRL9.