Silicon Materials (PP1.1)
PP1.1 Silicon Materials
The overall aim of the Silicon Materials work-package is to improve the quality and stability of silicon wafers, to enable higher efficiency solar cells in mass production.
The International Technology Roadmap for Photovoltaics (ITRPV) predicts that leading-product industrial cell efficiencies will increase from around 22.5% today to 24.5% in 10 years for p-type cells, and from 23% to 25% for n-type cells. Higher efficiency devices are more sensitive to wafer quality, and so these advances will only be achieved if the electronic quality of the silicon material itself is continuously improved. This, in turn, requires new advances in identifying and treating the key defects and impurities in these wafers - an increasingly challenging task as the defects become more dilute.
Continuing cell efficiency improvements will require further advances in our understanding and application of so-called impurity ‘gettering’ processes, which enable the removal of trace impurities during cell fabrication. Finally, advances in the passivation of residual defects by hydrogenation will be required, which plays a critical role in improving wafer quality during cell processing.
The activities will target the silicon materials most relevant for solar cell fabrication for industry, while also exploring emerging concepts for even lower cost silicon wafers.
Investigators: Bram Hoex (UNSW), Brett Hallam (UNSW), Alison Ciesla (UNSW), Malcolm Abbott (UNSW), Daniel Macdonald (ANU), AnYao Liu (ANU), Kelvin Sio (ANU).
The expected outcomes of the silicon materials work package will be a suite of new models, methods and tools for reducing the impact of defects and impurities in silicon wafers, enabling lower cost production of high quality, uniform, and stable silicon wafers. This will be a key element in enabling the production of silicon solar cells with efficiencies above 25% in mass production by 2030 and underwrite developments in silicon as a bottom cell in tandems targeting 30% efficiencies.