Achieving white-light emission in a single-component polymer with halogen-assisted interaction
作者:Zhuxin Zhou、Zhu Mao、Zhan Yang、Tingting Yang、Longji Zhu、Yubo Long、Zhenguo Chi、Siwei Liu、Matthew P. Aldred、Xudong Chen、Jiarui Xu、Yi Zhang
DOI:10.1007/s11426-020-9900-1
日期:2021.3
White-light emitting (WLE) polymers have attracted continuous attention for their promising applications in solid-state lighting, flexible display and related fields. However, achieving dual-emission and pure white-light emission in a single-component polymer is still challenging. In this study, a brominated single-component polymer BrOD-TFB was designed and synthesized, which shows dual-emission and white light emission properties in solution and room-temperature phosphorescence (RTP) in thin films. The dual-emission properties can be tuned by concentration, solvent polarity, and excitation energy. Spectral analyses and theoretical calculations reveal that the origin of the high-energy emission band (HEB) is intramolecular charge transfer (ICT) along the polymer chain, whilst the low-energy emission band (LEB) originates from the excited-state related to the intra-chain and inter-chain C-Br⋯π interactions as demonstrated by the single-crystal structure of the model compound. Appropriate control of the formation and the destruction of the halogen-assisted interactions can initiate white-light emission in the single-component polymer. More interestingly, by dispersing BrOD-TFB (0.1 wt%) in a non-emissive, colorless and transparent polymer, the characteristics of this white-light emission can be fully demonstrated while exhibiting unexpected RTP properties, with photoluminescence quantum efficiency (ΦPL) of up to 23% and CIE coordinates of (0.32, 0.32).
白光发光(WLE)聚合物因其在固态照明、柔性显示器及相关领域的广阔应用前景而备受关注。然而,在单组分聚合物中实现双发射和纯白光发射仍具有挑战性。本研究设计并合成了一种溴化单组分聚合物 BrOD-TFB,它在溶液中具有双发射和白光发射特性,在薄膜中具有室温磷光(RTP)特性。双发射特性可通过浓度、溶剂极性和激发能量进行调节。光谱分析和理论计算显示,高能发射带(HEB)源自聚合物链上的分子内电荷转移(ICT),而低能发射带(LEB)则源自与链内和链间 C-Br⋯π 相互作用有关的激发态,模型化合物的单晶结构也证明了这一点。适当控制卤素辅助相互作用的形成和破坏,可以在单组分聚合物中引发白光发射。更有趣的是,通过将 BrOD-TFB(0.1 wt%)分散在无发射性、无色透明的聚合物中,这种白光发射的特性可以得到充分展示,同时表现出意想不到的 RTP 特性,光致发光量子效率(ΦPL)高达 23%,CIE 坐标为(0.32, 0.32)。