Volatile solution: the way toward scalable fabrication of perovskite solar cells?

In the past decade, perovskite photovoltaics have achieved impressive progress in both efficiency and stability, bringing new insights and excitement in industrial sectors. Transitioning this technology from the laboratory to the industrial level first needs to overcome the crucial barrier of scalable fabrication. Although various synthetic routes have been developed for obtaining high-quality perovskite layers, there remains a gap between small-scale fabrication and industrial-level manufacturing, as the incumbent processing usually requires complex and energy-consuming treatments to remove the non-volatile solvents from those conventional perovskite inks. In this perspective, we conceptualize the volatile solution as an alternative ink system serving as a roadmap toward reliable manufacturing in the future. We discuss, starting from crystallization thermodynamics to insights into the chemistry ink system, its compatibility with various deposition techniques, and the analytic feasibility of scalable/stream-lined manufacturing using this new ink system. With this comprehensive minireview on the ongoing research and a discussion of its hypothetical potential/challenge, we hope to bring new inspiration and to catalyze the transition. As a quickly emerging photovoltaic technology, metal halide perovskite solar cells (PSCs) have attracted tremendous academic and industrial attention due to their unique features, such as wet chemical synthetic capability, high photovoltaic performance, and the potential to provide low carbon footprint.1?4 Remarkable progress has been achieved with use of PSCs with a rapidly growing power conversion efficiency (PCE).5, 6 The record PCE of 25.5% was achieved in 2020,7 which approached the previous record using monocrystalline silicon solar cells. The problem of the sta