Fully Spray-Coated Triple-Cation Perovskite Solar Cells

We use ultrasonic spray-coating to sequentially deposit thin films of tin oxide, a triple-cation perovskite and spiro-OMeTAD, allowing us fabricate perovskite solar cells (PSCs) with a champion reverse scan power conversion efficiency (PCE) of 19.4% on small-area substrates. We show that the use of spray-deposition permits us to rapidly (>80 mm s⁻¹) coat 25 mm × 75 mm substrates that were divided into a series of devices each with an active area of 15.4 mm², yielding an average PCE of 10.3% and a peak PCE of 16.3%. By connecting seven 15.4 mm² devices in parallel on a single substrate, we create a device having an effective active area of 1.08 cm² and a PCE of 12.7%. This work demonstrates the possibility for spray-coating to fabricate high efficiency and low-cost perovskite solar cells at speed.