Phase Engineering of Cesium Manganese Bromides Nanocrystals with Color‐Tunable Emission
Qingkun Kong, Bin Yang, Junsheng Chen, Ruiling Zhang, Siping Liu, Daoyuan Zheng, Hongling Zhang, Qingtong Liu, Yiying Wang, Keli Han
Abstract
Abstract For display applications, it is highly desirable to obtain tunable red/green/blue emission. However, lead‐free perovskite nanocrystals (NCs) generally exhibit broadband emission with poor color purity. Herein, we developed a unique phase transition strategy to engineer the emission color of lead‐free cesium manganese bromides NCs and we can achieve a tunable red/green/blue emission with high color purity in these NCs. Such phase transition can be triggered by isopropanol: from one dimensional (1D) CsMnBr 3 NCs (red‐color emission) to zero dimensional (0D) Cs 3 MnBr 5 NCs (green‐color emission). Furthermore, in a humid environment both 1D CsMnBr 3 NCs and 0D Cs 3 MnBr 5 NCs can be transformed into 0D Cs 2 MnBr 4 ⋅2 H 2 O NCs (blue‐color emission). Cs 2 MnBr 4 ⋅2 H 2 O NCs could inversely transform into the mixture of CsMnBr 3 and Cs 3 MnBr 5 phase during the thermal annealing dehydration step. Our work highlights the tunable optical properties in single component NCs via phase engineering and provides a new avenue for future endeavors in light‐emitting devices.