Full color emission of all-bromide inorganic perovskite nanocrystals

Abstract

Inorganic perovskites have attracted intensive research attention. The perovskites ABX3 (X = Cl, Br, and I) can be used for blue, green, and red emission by adjusting the halogen X. However, it is very hard to avoid halogen exchanging when different halide perovskites are used together for optoelectronic devices. We synthesized the all-bromide inorganic perovskite nanocrystals with full color emission. The blue emission with a center wavelength of 405 nm originates from the exciton recombination through the charge-transfer exciton state in perovskite Cs4PbBr6. The green emission with a center wavelength of 520 nm results from band edge-exciton recombination in perovskite CsPbBr3. The red emission with a center wavelength of 606 nm comes from the trapped- and self-trapped-exciton recombination in perovskite CsPb2Br5. Our experimental results show that all-bromide inorganic perovskite nanocrystals have great potential for full color light emitting devices.