Efficient Perovskite Solar Cells Prepared by Hot Air Blowing to Ultrasonic Spraying in Ambient Air.

Substrate heating is the most common method for controlling crystallization during spray coating. However, due to poor controllability during substrate heating, the sprayed films have variable thicknesses and rich pores, which limit the efficiency of the device. Here, hot air blowing was applied to spray coating to promote the crystallization of perovskite films under ambient conditions. Upon employing a hot air blowing method that stimulated uniformly distributed nuclei growth, the pinhole-free and thickness-controllable perovskite film was prepared. This enabled more reproducible high-quality perovskite films to achieve a power conversion efficiency of 13.5% and obtain a stabilized power output of >12% in ambient conditions.