High Efficiency, Multi-Junction CPV Solar Cells

Summary

Need

Lower cost and high efficiency concentrating photovoltaic (CPV) cells are required to maximise the dense array dish technology pioneered by Solar Systems Pty Ltd.

Project innovation

The High Efficiency, Multi-Junction CPV Solar Cells project is developing virtual germanium (Ge) and germanium-tin (Ge-Sn) on silicon wafers for the next generation of multiple-junction solar cells, which are low in cost but highly efficient, meaning they can convert more energy from sunlight than most other solar cells.

Multiple-junction solar cells are currently fabricated on expensive Ge wafer substrates (the bottom layer of a solar cell) that are not ideal for CPV systems. This project will allow development of the germanium-tin-silicon material system, which offers an alternative way to produce the CPV cell material needed to generate ultra high efficiency.

The key element of this project is the development of the new ‘virtual germanium-on-silicon’ and germanium-tin on silicon substrates where a thin layer of Ge of Ge-Sn is deposited on a silicon wafer. This could significantly reduce the cost and potentially improve the efficiency of the multiple-junction solar cell when used in CPV applications.

The new substrates and resulting CPV cells will be fully analysed in the laboratory and then tested in the field at Solar Systems’ Bridgewater test facility.

Once commercialised the technology would be available for large utility-scale concentrating photovoltaic power plants such as Solar Systems’ Solar Concentrator Power Project in Mildura, north-west Victoria.

Benefit

Combining Solar Systems’ dense array dish system with new ‘virtual’ multi-junction solar cells could revolutionise utility-scale photovoltaic systems in terms of cost and efficiency, producing around 1000 times the amount of energy as a roof-mounted flat plate photovoltaic panel with the same area of solar cells.