Efficient monolithic perovskite/silicon tandem solar cells via optimized perovskite front-layer stack integrated with industry-scalable silicon bottom cell technologies

This thesis examines the development of high-efficiency monolithic perovskite-silicon tandem solar cells by optimizing the integration of perovskite front-layer stacks with scalable silicon bottom cell technology. This study aims to improve power conversion efficiency and long-term stability by tackling critical issues in material deposition, device architecture, and fabrication methods. A crucial aspect of the research involves improving the atomic layer deposition (ALD) of tin oxide (SnOx) to function as an effective buffer layer against sputter-induced damage. Additionally, the use of multifunctional polymeric interlayers, such as polyethyleneimine, is investigated to facilitate a better growth of high-quality tin oxide films, reduce interfacial traps, and enhance overall device efficiency. Extensive collaboration with industrial partners enabled the fabrication of indutry-like silicon bottom cells utilizing TOPCon next to silicon heterojunction (SHJ) technologies to reach industry-relevant scalability. A comparative investigation of several perovskite compositions and interlayer materials identified strategies to diminish non-radiative recombination losses and optimize open-circuit voltage (VOC). The final tandem solar cell configuration attained a record power conversion efficiency of 30% for ALD-free monolithic perovskite/silicon tandem solar cells based on PERx/Topcon silicon bottom cells, illustrating the feasibility for extensive application of this technology.