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

Recently, all-inorganic halide perovskite (CsPbX , (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 TiO @CsPbBr hybrid architectures, in which TiO nanoparticles (NPs) with a hard lattice as nano "balls" mill off the angles and anchor to the CsPbBr NCs with a soft lattice. On the contrary, to ball-mill without TiO or with conventional ceramics balls replacing TiO , CsPbBr NCs still maintain cubic contour deriving from their cubic crystal structures. Moreover, the TiO @CsPbBr architectures display distinct improvement of photoluminescence quantum yields and more excellent thermal stability in contrast with pristine CsPbBr owing to the passivation of surface defect, small surface area, and energy transfer from CsPbBr to TiO . Meanwhile, there is distinct luminous decay characteristic under the radiation of UV and visible light due to the "on" and "off" TiO response. The method provides an alternative strategy to acquire other anchoring heterojunctions based on perovskite NCs for further regulating their luminescent characteristics.