Organic–inorganic halide perovskites (OIHPs) have attracted tremendous attention because of their outstanding and tunable optoelectronic properties. While the progress of perovskite solar cells (PSCs) through laboratory-scale deposition methods is promising in efficiency, there are still many technological issues to address, including the process transfer from laboratory-scale fabrication to industrial-scale mass production, especially under ambient conditions (preferably with a high tolerance to humidity), to realize their low-cost promise. In this review, we summarize the most recent progress in the upscaling of PSCs processed in an ambient environment. Along with discussing the underlying challenges and limitations, we provide a brief overview of robust strategies for the fabrication of efficient PSCs using printing-friendly techniques under ambient conditions, which are crucial for the future deployment of this exciting technology.
