Atmospheric Humidity Underlies Irreproducibility of Formamidinium Lead Iodide Perovskites

• Published in: Advanced materials (Weinheim) Vol. 36; no. 14; pp. e2307265 - n/a
• Main Authors: Park, Keonwoo, Tan, Shaun, Kodalle, Tim, Lee, Do‐Kyoung, Abdelsamie, Maged, Park, Ji‐Sang, Lee, Joo‐Hong, Jung, Sung‐Kwang, Ko, Jeong Hoon, Park, Nam‐Gyu, Sutter‐Fella, Carolin M., Yang, Yang, Lee, Jin‐Wook
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 01.04.2024
• Subjects: Commercialization; Crystallization; crystallizations; halide perovskites; Humidity; in situ studies; Laboratories; Metal halides; Optoelectronics; Perovskites; Photovoltaic cells; reproducibility; scalability; Solar cells; Stability; Stoichiometry; in situ studies; reproducibility; crystallizations; humidity; halide perovskites; solar cells; scalability; stability
• ISSN: 0935-9648; 1521-4095
• DOI: 10.1002/adma.202307265

Metal halide perovskite solar cells (PSCs) are infamous for their batch‐to‐batch and lab‐to‐lab irreproducibility in terms of stability and performance. Reproducible fabrication of PSCs is a critical requirement for market viability and practical commercialization. PSC irreproducibility plagues all levels of the community; from institutional research laboratories, start‐up companies, to large established corporations. In this work, the critical function of atmospheric humidity to regulate the crystallization and stabilization of formamidinium lead triiodide (FAPbI3) perovskites is unraveled. It is demonstrated that the humidity content during processing induces profound variations in perovskite stoichiometry, thermodynamic stability, and optoelectronic quality. Almost counterintuitively, it is shown that the presence of humidity is perhaps indispensable to reproduce phase‐stable and efficient FAPbI3‐based PSCs. Atmospheric humidity control during the fabrication process crucially influences the phase formation and stability of formamidinium perovskites. This work reveals that controlled humidity during the fabrication process is a key to achieving reproducible fabrication of high‐quality and stable perovskite films. Thus, precise humidity management is essential to ensure the reproducible, efficient, and stable perovskite solar cells.