Impact of Hole Transporting Layers on the Composition of Chemical Vapor Deposited Perovskite and Performance of Semitransparent Solar Cells

Low-pressure chemical vapor deposition (CVD) offers good scalability, substrate compatibility, and solvent-free processing for metal halide perovskite films fabrication, yet limited control over the film composition has hindered the device performance compared to solution-based methods. Herein, we investigate how the substrate surface property affect the composition and optoelectronic properties of perovskite films fabricated by CVD. By changing the hole transporting layers (HTLs), different crystallization process and chemical stoichiometry of perovskite films have been observed. Perovskite films grown on nickel oxide|self-assembled monolayers (SAMs) exhibit a more stoichiometric buried surface, along with a higher work function (WF) and enhanced p-type character that are favorable for hole transport. Leveraging these insights, we demonstrate all vapor-deposited semitransparent perovskite solar cells (ST-PSCs) with a champion efficiency of 18.0%, retaining ∼100% of the initial performance after 500 h of continuous operation (ISOS-L-1). Furthermore, we achieve a champion efficiency of 17.5% for semitransparent mini-modules fabricated via the all-vacuum process.