题目：

Atomically unraveling the   structural evolution of surfaces and interfaces in metal halide perovskite   quantum dots

作者：

Mengmeng Ma, Xuliang   Zhang, Liang Xu, Xiao Chen, Lei Wang, Tao Cheng, Fei Wei, Jianyu Yuan*,   Boyuan Shen*

摘要：

Revealing the local structural change of metal halide perovskites   (MHPs) induced by external conditions is important to understand its   performance and stability in optoelectronic applications. However, previous   studies on the properties and structures of MHPs are usually limited by the   spatial resolution of the probe, and it is still challenging to obtain its   atomic structural information in real space. In this work, the integrated   differential-phase-contrast scanning transmission electron microscopy is applied   to the low-dose imaging of CsPbI3 quantum dots (QDs). In particular, the   local structures in QDs, such as surfaces and interfaces, can be atomically   resolved. Then, the structural evolution of CsPbI3 QDs under various external   conditions can be unraveled during in situ heating or ex situ treatments,   where it lose cubic shapes and fuse to larger particles. The changes in   surfaces and interfaces with missing Cs ions and PbI6 octahedrons can be   semi-quantitatively studied by profile analysis and bond-length measurement   in images. Finally, density functional theory calculations are performed to   illustrate the properties and stabilities of the different structures that   are observed. These results provide atomic-scale insights into the structural   evolution of QDs, which is of great importance to modify the performance of   perovskite materials and devices.

影响因子：

30.849

分区情况：

一区