Scalable and efficient perovskite solar cells prepared by grooved roller coating

Small-area perovskite solar cells (PSCs), prepared by a spin-coating technique have rapidly achieved an excellent power conversion efficiency (PCE) of 23.3% and improved stability. Large-area and efficient PSCs prepared by the scalable deposition technique are urgently required for continuous mass production. Herein, high quality perovskite films and devices have been prepared via a newly developed grooved roller coating (GRC) technique. A critical groove depth of 6 μm has been proven to generate uniform perovskite films with average 594 nm sized grains and a shifted dominant plane from (110) to (224). Time-resolved photoluminescence confirms the balanced interfacial charge transfer (60.8 ns) and bulk transport life time (140.6 ns) for efficient PSCs. GRC-prepared perovskite films demonstrate competitive qualities compared with those prepared by a standard spin-coated (SSC) technique, based on both of which PSC shows a similar PCE of 15.26% for the GRC and 15.76% for the SSC. Finally, the PSCs based on fully roller-coated SnO2, perovskite and spiro-OMeTAD achieve a PCE of 12.34%, which is the highest PCE value obtainable by the roller coating technique and the first PCE obtained by fully roller coating. Therefore, the results predict that GRC could be a facile and effective method for large-area and continuous mass production of PSCs for future commercialization.