Unlocking the potential of CsPbI3 perovskite as stable red phosphors by zeolite skeleton

CsPbI3 perovskite-based phosphors are ideal candidates for red/near-infrared light-emitting diodes (LEDs). However, they suffer from poor stability and low photoluminescence quantum yields (PLQYs). Herein, CsPbI3@zeolite composites with bright, deep-red, solid-state fluorescence have been successfully developed by a high-temperature calcination followed by water treatment strategy. The composites possess PLQYs of 31.1% and exceptional stability even comparable to that of commercial phosphors. Such properties are rarely reported in solid-state CsPbI3 perovskite systems. Studies show that removing the non-luminous by-products and controlling the thickness of the zeolite shell are essentials for enhancing the PLQYs, and the excellent stability results from the tight encapsulation of CsPbI3 perovskite by the host skeleton. As a proof of concept, standard red and white LEDs with a maximal luminous efficiency of 57.3 lm/W and excellent long-term operation stability are constructed based on the as-made composites. This work unlocks the application potential of CsPbI3 perovskite as stable red phosphors.