With commercial silicon solar cells approaching both practical and theoretical efficiency limits, there is growing research effort to develop new low-cost technologies capable of reaching efficiencies of 30% and beyond.

With commercial silicon solar cells approaching both practical and theoretical efficiency limits, there is growing research effort to develop new low-cost technologies capable of reaching efficiencies of 30% and beyond. Silicon-based tandems that combine current industrial technology with emerging thin-film PV materials are considered the most cost-effective option for achieving this, with the latest edition of the International Technology Roadmap for Photovoltaics (ITRPV) predicting Si-based tandems to appear in mass production after 2019. The rapid rise of perovskite solar cell performance in the past few years has made perovskites the material of choice as a top cell for such tandems due to their high efficiency and simple, low-cost fabrication. This presentation will identify the challenges and prospects for perovskite-silicon tandems to surpass the efficiency limits of single-junction silicon cells, and will discuss the research developments that led to our recent demonstration of a 26.4% perovskite-silicon tandem.  It will also identify the pathway to further efficiency gains, as well as the key challenges to commercialisation.