Improving the Stability of CsPbBr3 Perovskite Nanocrystals by Peroxides Post-treatment

Metal oxides exhibit excellent barrier properties against moisture and oxygen, which are regarded as the powerful candidate for boosting the stability of perovskite nanocrystals (NCs). Here, we develop a simple method to coat perovskite NCs with PbO by peroxides post-treatment. Firstly, the didodecyl dimethyl ammonium sulfide (DDAS) was used to modify the CsPbBr3 NCs (DDAS-CsPbBr3), and then sequentially treated with benzoyl peroxide (BPO). By this way, the self-metal source (lead) can be easily oxidized, leading to the quick growth of lead oxide (PbO) on the surface of individual CsPbBr3 NCs. Under illumination with a 450 nm LED light (175 mW/cm2), the PbO coated CsPbBr3 NCs maintained at ~90% of the initial intensity for 20 h of operations; in contrast, the emission from the CsPbBr3 NCs completely quenched.