Advances in Spray-Cast Perovskite Solar Cells.

Spray-coating is a deposition technique that is widely used in industry and could in principle be used to fabricate perovskite photovoltaic (PV) devices at low cost and high volume. As with any deposition technique, the fabrication of thin films requires optimization of a range of parameter space in order to control film uniformity and homogeneity. This is particularly important in PV fabrication as the quality of the thin film has an important effect on device efficiency. This Perspective summarizes the developments in spray-cast perovskite solar cells made over the past few years, with particular attention paid to strategies employed to control the crystallization of the perovskite. Steady progress has now been made with spray-cast perovskite PV devices recently demonstrated having a power conversion efficiency of 18.3%. We highlight trends within the research field and discuss challenges that will be necessary to drive such techniques toward practical application.