Chloride-incorporated quasi-2D perovskite films via dynamic processing for spectrum-stable blue light-emitting diodes

Compared with the rapid development of red and green perovskite light-emitting diodes (PeLEDs), the improvement of the device performance is urgent for blue PeLEDs. Herein, we developed a creative method to incorporate Cl- into quasi-2D perovskite films via dynamic processing, by mixing two main strategies of mixed-Cl/Br perovskites and quasi-2D perovskites. With methylammonium chloride (MACl) treating the perovskite film, the devices presented excellent spectral stability owing to the effective suppression of non-radiative recombination. Consequently, CsPbBr3 : PEABr-based PeLEDs exhibited a maximum external quantum efficiency of 1.74% with a bright luminance of 537 cd m(-2). The redshift of the emitting luminescence (EL) peak was no more than 2 nm around 477 nm. The findings in this work will help develop other new routes for pure blue PeLEDs with ideal spectral stability.