Neogi Ishita, Bruno Annalisa, Bahulayan Damodaran, Goh Teck Wee, Ghosh Biplab, Ganguly Rakesh, Cortecchia Daniele, Sum Tze Chien, Soci Cesare, Mathews Nripan, Mhaisalkar Subodh Gautam
Energy Research Institute, Nanyang Technological University, Research Techno Plaza, X-Frontier Block, Level 5, 50 Nanyang Drive, 637553, Singapore, Singapore.
School of Physical and Mathematical Science, Nanyang Technological University, 21 Nanyang Link, 637371, Singapore, Singapore.
ChemSusChem. 2017 Oct 9;10(19):3765-3772. doi: 10.1002/cssc.201701227. Epub 2017 Aug 24.
A new broadband-emitting 2 D hybrid organic-inorganic perovskite (CyBMA)PbBr based on highly flexible cis-1,3-bis(methylaminohydrobromide)cyclohexane (CyBMABr) core has been designed, synthesized, and investigated, highlighting the effects of stereoisomerism of the templating cation on the formation and properties of the resulting perovskite. The new 2 D material has high exciton binding energy of 340 meV and a broad emission spanning from 380 to 750 nm, incorporating a prominent excitonic band and a less intense broad peak at room temperature. Significant changes in the photoluminescence (PL) spectrum were observed at lower temperatures, showing remarkable enhancement in the intensity of the broadband at the cost of excitonic emission. Temperature-dependent PL mapping indicates the effective role of only a narrow band of excitonic absorption in the generation of the active channel for emission. Based on the evidences obtained from the photophysical investigations, we attributed the evolution of the broad B-band of (CyBMA)PbBr to excitonic self-trapped states.
基于高度柔性的顺式-1,3-双（甲基氨基氢溴化物）环己烷（CyBMABr）核，设计、合成并研究了一种新型宽带发射二维有机-无机杂化钙钛矿（CyBMA）PbBr，突出了模板阳离子的立体异构对所得钙钛矿形成和性质的影响。这种新型二维材料具有340 meV的高激子结合能和380至750 nm的宽带发射，在室温下包含一个突出的激子带和一个较弱的宽峰。在较低温度下观察到光致发光（PL）光谱有显著变化，显示宽带强度显著增强，但以激子发射为代价。温度依赖的PL映射表明，只有窄带激子吸收在发射活性通道的产生中起有效作用。基于光物理研究获得的证据，我们将（CyBMA）PbBr的宽B带的演变归因于激子自陷态。
