Institute of Optoelectronics & Nanomaterials, MIIT Key Laboratory of Advanced Display Material and Devices, College of Materials Science and Engineering, Nanjing University of Science and Technology , Nanjing 210094, China.
National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University , Nanjing 210093, China.
ACS Appl Mater Interfaces. 2017 Nov 15;9(45):39602-39609. doi: 10.1021/acsami.7b12048. Epub 2017 Nov 1.
Low-dimensional halide perovskite (HP) has triggered lots of research attention in recent years due to anisotropic optoelectronic/semiconducting properties and enhanced stability. High-quality low-dimensional HPs via controllable engineering are required to fulfill the encouraging promise for device applications. Here, we introduce, for the first time, postsynthetic ultrasonic-assisted refinement of two-dimensional homologous HPs (OAPbBr, OA is octadecylamine). The solution-prepared OAPbBr, either in the form of large-sized microcrystal or nanosheet, obtains significantly enhanced crystallinity after ultrasonic treatment. We further show that OAPbBr nanosheets can be used as a template to construct low-dimensional CsPbBr with the size and morphology inherited. Importantly, we found the ultrasonic-treated OAPbBr crystals, compared with pristine ones, lead to enhanced optoelectronic properties for the resultant low-dimensional CsPbBr, as demonstrated by improved photodetection performances, including prolonged charge-carrier lifetime, improved photostability, increased external quantum yield/responsivity, and faster response speed. We believe this work provides novel engineering of low-dimensional HPs beyond the reach of straightforward synthesis.
近年来，由于具有各向异性的光电/半导体性质和增强的稳定性，低维卤化物钙钛矿（HP）引起了大量的研究关注。需要通过可控工程来获得高质量的低维 HP，以实现对器件应用的鼓舞人心的承诺。在这里，我们首次介绍了通过后合成超声辅助细化二维同系物 HP（OAPbBr，OA 是十八胺）。经过超声处理后，无论是大尺寸微晶体还是纳米片形式的溶液制备的 OAPbBr，其结晶度都得到了显著提高。我们进一步表明，OAPbBr 纳米片可用作模板来构建具有尺寸和形貌继承性的低维 CsPbBr。重要的是，我们发现与原始晶体相比，经超声处理的 OAPbBr 晶体导致所得低维 CsPbBr 的光电性能得到增强，表现为光电探测性能的提高，包括载流子寿命延长、光稳定性提高、外量子效率/响应率增加和响应速度加快。我们相信这项工作提供了低维 HP 的新型工程设计，超越了直接合成的范围。
