Febriansyah Benny, Borzda Tetiana, Cortecchia Daniele, Neutzner Stefanie, Folpini Giulia, Koh Teck Ming, Li Yongxin, Mathews Nripan, Petrozza Annamaria, England Jason
Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore, 637371, Singapore.
Energy Research Institute at Nanyang Technological University (ERI@N), Research Techno Plaza, X-Frontier Block Level 5, 50 Nanyang Drive, Singapore, 637553, Singapore.
Angew Chem Int Ed Engl. 2020 Jun 26;59(27):10791-10796. doi: 10.1002/anie.201915708. Epub 2020 May 7.
Published studies of layered (2D) (100)-oriented hybrid lead-bromide perovskites evidence a correlation between increased inter-octahedral (Pb-Br-Pb) distortions and the appearance of broadband white light emission. However, the impact of distortions within their constituent [PbBr ] octahedra has yet to be assessed. Herein, we report two new (100)-oriented 2D Pb-Br perovskites, whose structures display unusually high intra-octahedral distortions, whilst retaining minimal inter-octahedral distortions. Using a combination of temperature-dependent, power-dependent and time-resolved photoluminescence spectroscopic measurements, we show that increased intra-octahedral distortion induces exciton localization processes and leads to formation of multiple photoinduced emissive colour centres. Ultimately, this leads to highly Stokes-shifted, ultrabroad white light emission at room temperature.
已发表的关于层状（二维）（100）取向的混合铅溴钙钛矿的研究表明，八面体间（Pb-Br-Pb）畸变增加与宽带白光发射的出现之间存在关联。然而，其组成的[PbBr]八面体内部畸变的影响尚未得到评估。在此，我们报道了两种新的（100）取向的二维Pb-Br钙钛矿，其结构显示出异常高的八面体内畸变，同时保持最小的八面体间畸变。通过结合温度依赖、功率依赖和时间分辨光致发光光谱测量，我们表明八面体内畸变增加会诱导激子局域化过程，并导致形成多个光致发光色心。最终，这导致在室温下产生高度斯托克斯位移的超宽带白光发射。
