Near‐Unity Superradiant Emission from Delocalized Frenkel Excitons in a Two‐Dimensional Supramolecular Assembly
Near‐Unity Superradiant Emission from Delocalized Frenkel Excitons in a Two‐Dimensional Supramolecular Assembly
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DOI：
10.1002/adom.202201471
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发表时间：
2022-11
影响因子：
9
通讯作者：
U. Barotov;D. T. W. Arachchi;Megan D. Klein;Juanye Zhang;Tara Šverko;M. Bawendi
中科院分区：
文献类型：
--
作者：
U. Barotov;D. T. W. Arachchi;Megan D. Klein;Juanye Zhang;Tara Šverko;M. Bawendi
三个一般有效的策略，以减轻非辐射损失的超分子组件的超辐射发射。用5，5 ′，6，6 ′-四氯-1，1 ′-二乙基-3，3 ′-二（4-磺丁基）-苯并咪唑羰花青（TDBC）的J-聚集体研究了无辐射过程的性质.在室温（RT）下的自退火、光致增亮和染料单体的纯化均显示出导致发射量子产率（QY）的显著增加和伴随的发射寿命的延长，其中纯化具有最大的效果。结构和光学测量是用来支持一个微观模型，强调作为非辐射复合中心的杂质和缺陷的少数网站的有害影响。这种理解已经产生了在溶液中的分子荧光团在RT与快速发射寿命和高QY的前所未有的组合。在室温下，从TDBC溶液中的J-聚集体获得了QY为82%和寿命为174 ps的超辐射发射。这种高QY和快速寿命的组合使纯化的TDBC超分子组装体成为研究基本超辐射现象的模型系统。高QY J‐aggregates特别适合需要高速和高亮度荧光团的应用开发，例如高速光通信设备。
Three general effective strategies are shown to mitigate nonradiative losses in the superradiant emission from supramolecular assemblies. J‐aggregates of 5,5′,6,6′‐tetrachloro‐1,1′‐diethyl‐3,3′‐di(4–sulfobutyl)‐benzimidazolocarbocyanine (TDBC) are used to elucidate the nature of nonradiative processes. Self‐annealing at room temperature (RT), photo‐brightening, and purification of the dye monomers are shown to all lead to substantial increases in emission quantum yields (QYs) and a concomitant lengthening of the emission lifetime, with purification having the largest effect. Structural and optical measurements are used to support a microscopic model that emphasizes the deleterious effects of a small number of impurity and defect sites that serve as nonradiative recombination centers. This understanding has yielded a molecular fluorophore in solution at RT with an unprecedented combination of fast emissive lifetime and high QY. Superradiant emission with a QY of 82% and a lifetime of 174 ps is obtained from J‐aggregates of TDBC in solution at RT. This combination of high QY and fast lifetime at RT makes supramolecular assemblies of purified TDBC a model system for the study of fundamental superradiance phenomena. High QY J‐aggregates are uniquely suited for the development of applications that require high speed and high brightness fluorophores such as devices for high‐speed optical communication.