Shunt mitigation toward efficient large-area perovskite-silicon tandem solar cells
Guang Yang, Zhengshan J. Yu, Mengru Wang, Zhifang Shi, Zhenyi Ni, Haoyang Jiao, Chengbin Fei, Allen Wood, Abdulwahab Alasfour, Bo Chen, Zachary C. Holman, Jinsong Huang
Abstract
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.