Self-spreading produces highly efficient perovskite solar cells

A facile two-step drop-coating method was used to make FA(0.88)MA(0.12)PbI(x)Br(3-x) (0 <= x <= 3) perovskite films for the first time. The films formed via a self-spreading process, without the assistance of coating apparatuses, gas blowing, vacuum, or antisolvent. High-quality perovskite films with different bandgaps were made and the photovoltaic performance was investigated. The cells with FA(0.88)MA(0.12)PbI(2.85)Br(0.15) offered a champion PCE of 21.08%, which is higher than the PCEs for perovskite solar cells made by other two-step non-spin-coating methods. The FA(0.88)MA(0.12)PbBr(3) cells gave a champion PCE of 10.86%, which is the highest PCE for FA(x)- MA(1-x)PbBr(3) cells. The drop-coating method enables making perovskite solar cells without complex equipment. Fully handmade perovskite solar cells with drop-coated SnO2, drop-coated perovskite, and painted carbon electrode were made in air, giving a PCE of 14.04%.

Automated summary

A facile drop-coating method was used to make FA(0.88)MA(0.12)PbI(x)Br(3-x) perovskite films, resulting in high-quality films with different bandgaps and efficient solar cells. The champion PCE reached 21.08% for FA(0.88)MA(0.12)PbI(2.85)Br(0.15) cells, demonstrating the potential of this simple fabrication technique.