Design considerations for the bottom cell in perovskite/ silicon tandems

Perovskite/silicon tandems have smashed through the 30% efficiency barrier, which represents a promising step towards high efficiency solar modules.  The processing used to fabricate high efficiency devices, however, is not compatible with mass production.

For this technology to be impactful in the urgent fight against climate change and to be scalable to the multi-terawatt (TW) level, a shift in mindset is required when designing the silicon bottom cell.  In this work, a team from CSIRO Energy (Newcastle Energy Circuit, Australia), The University of New South Wales and the Department of Physics (Oxford) were led by Dr Matthew Wright of this department, outline the design requirements for the silicon cell, with a particular focus on the constraints imposed by industrial processing.  The type of silicon wafer used is presented, as well as the surface treatment, the most appropriate silicon cell architecture and the formation of metal contacts.  The team additionally frame their work in the context of multi-TW markets, which impose additional constraints on the processing relating to the sustainability of the materials used.  The discussion within their paper ('Design considerations for the bottom cell in perovskite/silicon tandems: a terawatt scalability perspective') will help shape the design of future silicon solar cells for use in tandems, so that the LCOE of solar electricity can be driven to new lows.