Air-Processed Perovskites Enabled by an Interface-Reconstruction Strategy for High-Performance Light-Emitting Diodes.

Fabricating high-performance perovskites in ambient air is desirable for low-cost and large-scale patterned manufacture of light-emitting diodes (LEDs). However, perovskites inherently exhibit high sensitivity to moisture and oxygen, which considerably hinders their fabrication under ambient air conditions. Here, we demonstrated an interface-reconstruction strategy which enabled air-processed CsPbI quantum dot (QD) films for high-performance LEDs. Ethyl acetate/tris(1-naphthyl)phosphine oxide (EA/TNPO) treatment was used to polish and passivate the interface between the QD film and the electron transport layer, thereby providing a protective coating against moisture and oxygen. We fabricated LEDs based on the spin-coated QD films, achieving a maximum external quantum efficiency (EQE) of 20.2% and a long half-life of over 100 days. We also fabricated LEDs based on the inkjet-printed QD films, highlighting the practical application potential for patterning techniques. Our work develops high-quality air-processed perovskite films and demonstrates their great prospect for low-cost optoelectronic devices in the future.