Shunt mitigation toward efficient large-area perovskite-silicon tandem solar cells

The efficiency of small-area perovskite-silicon tandem solar cells is already above 30%; however, there are few studies about large-area tandem cells. One main challenge for the upscaling of perovskite-silicon tandems is the non-uniformity of perovskites across large areas of tandem cells that can cause shunting, which becomes more serious when large-area tandems are fabricated via a solution process. Here, we demonstrate the fabrication of efficient large-area tandems on industry-compatible Czochralski-grown and chemically etched rough silicon wafers using a blading process. We employed a lithium fluoride (LiF) interlayer to significantly mitigate the shunting issue for large-area tandems when it is deposited on the hole transport layer side. The LiF interlayer decreases local current drains and improves interfacial contact at the buried perovskite interface. As a result, a stabilized power conversion efficiency of 25.1% is achieved for tandem devices with a large aperture area of 24 cm2.