Ultrafast, scalable fabrication of mechanically robust perovskite films

Stanford researchers have developed a new way to deposit robust and efficient photoactive perovskite materials in open-air and at rapid linear processing rates in excess of 1 cm/s. By coupling ultrasonic spray coating to the reactive environment of a plasma, this one step process minimizes manufacturing speed and the volume of raw materials without any external heating, while resulting in the world's toughest perovskite thin film. Atmospheric plasma is used to rapidly cure photoactive perovskite films in ambient air, resulting in thin films with enhanced mechanical integrity. This method, Rapid Spray Plasma Processing (RSPP), enables deposition of metal halide perovskite films in open air at an ultrafast linear processing rate. The atmospheric plasma system can easily be adopted and adapted on a roll-to-roll or sheet coating processes.

Figure

Figure description -Material deposition system and MAPbI₃ sample picture. (a) Atmospheric plasma deposition system for the synthesis of perovskite films. a is the plasma nozzle-to-substrate distance, b is the spray nozzle-to-substrate distance and c is the plasma nozzle-to-spray nozzle distance. (b) Photograph of a MAPbI₃ film deposited by RSPP on a 930 cm² glass in under 4 min.

Stage of Research

Experimental Results - In an open air environment, films were sprayed and immediately exposed to an atmospheric plasma to form crystalline and photoactive metal halide perovskite. No additional annealing or post-deposition processing is required. Furthermore, RSPP has a high conversion yield; in contrast to spin coating which may require up to 50 ?L/cm², RSPP requires around 1 ?L/cm².

Device was capable of obtaining 13% PCE and a V_OC of 1 V in an inverted PSC