Back-contact perovskite solar cells: progress, challenges and the future

Back-contact solar cells are a novel type of device architecture that have been used in combination with both silicon and perovskite semiconductors. Since 2016, the efficiencies of perovskite back-contact solar cells have risen from 6.5% to over 11%, with a wide variety of fabrication methods and device structures employed. This Spotlight on Applications article aims to highlight the benefits of back-contact solar cells over more routinely used planar counterparts and reviews recent progress made using perovskite materials. In particular, we show how the use of substrates patterned with embossed microgrooves presents a facile route to back-contact solar-cell scale-up, with this approach recently used to create perovskite solar-cell modules consisting of hundreds of serially connected grooves having a stabilized efficiency of up to 12.8%. We conclude by discussing the challenges required to drive this technology toward high-volume manufacture and commercialization.