Nano Ball-Milling Using Titania Nanoparticles to Anchor Cesium Lead Bromine Nanocrystals and Energy Transfer Characteristics in TiO 2 @CsPbBr 3 Architecture.

Recently, all-inorganic halide perovskite (CsPbX3, (X = Cl, Br, and I)) nanocrystals (NCs) based hybrid architectures have attracted extensive attention owing to their distinct luminescence characteristics. However, due to stress and lattice mismatch, it is still a challenge to construct heterojunctions between perovskite NCs and the nanostructures with different lattice parameters and non-cubic contour. In this work, a room temperature mechanochemical method is presented to construct TiO2@CsPbBr(3)hybrid architectures, in which TiO(2)nanoparticles (NPs) with a hard lattice as nano "balls" mill off the angles and anchor to the CsPbBr3NCs with a soft lattice. On the contrary, to ball-mill without TiO(2)or with conventional ceramics balls replacing TiO2, CsPbBr3NCs still maintain cubic contour deriving from their cubic crystal structures. Moreover, the TiO2@CsPbBr(3)architectures display distinct improvement of photoluminescence quantum yields and more excellent thermal stability in contrast with pristine CsPbBr(3)owing to the passivation of surface defect, small surface area, and energy transfer from CsPbBr(3)to TiO2. Meanwhile, there is distinct luminous decay characteristic under the radiation of UV and visible light due to the "on" and "off" TiO(2)response. The method provides an alternative strategy to acquire other anchoring heterojunctions based on perovskite NCs for further regulating their luminescent characteristics.