Reports on highly efficient silver(I)-based thermally activated delayed fluorescence (TADF) materials are scarce due to challenges in molecular design, although these materials show great potential for photoluminescent and electroluminescent applications. Herein, a silver(I)–iodine cluster, namely Ag₂I₂(dppb-Ac)₂, is synthesized by employing a donor–acceptor (D–A) type bisphosphine ligand. Due to the introduction of electron-donating iodine ligands, Ag₂I₂(dppb-Ac)₂ exhibits an emissive singlet state characterized by (metal + iodine)-to-ligand charge transfer and intra-ligand charge transfer transitions, as well as a small singlet–triplet energy gap. Additionally, its non-planar, highly distorted D–A structure efficiently separates adjacent molecules in aggregated state. As a result, Ag₂I₂(dppb-Ac)₂ exhibits efficient TADF and suppressed luminescence concentration quenching in thin films. For instance, the 10 wt%-doped PMMA film and neat film of Ag₂I₂(dppb-Ac)₂ display bright bluish-green and green emission, peaking at 506 and 532 nm, with photoluminescence quantum yields (PLQYs) of 70% and 52%, and lifetimes of 18.9 and 7.9 μs, respectively. The high PLQYs and efficiently suppressed emission concentration quenching of Ag₂I₂(dppb-Ac)₂ in films are outstanding among reported Ag(I)-based TADF emitters.

中文翻译：

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银 （I）-碘簇，具有高效的热激活延迟荧光和抑制的浓度淬灭


由于分子设计的挑战，关于高效银基热激活延迟荧光 （TADF） 材料的报道很少，尽管这些材料在光致发光和电致发光应用方面显示出巨大的潜力。在此，银 （） - 碘簇，即 Ag₂I₂ （dppb-Ac）₂ ，是通过采用供体-受体 （D-A） 型双膦配体合成的。由于引入了供电子碘配体，Ag₂I₂（dppb-Ac）₂ 表现出发射单重态，其特征是（金属 + 碘）-配体电荷转移和配体内部电荷转移转变，以及一个小的单重态-三重态能隙。此外，其非平面、高度扭曲的 D-A 结构可有效分离聚集状态的相邻分子。因此，Ag₂I₂（dppb-Ac）₂ 在薄膜中表现出有效的 TADF 和抑制的发光浓度猝灭。例如，10 wt% 掺杂的 PMMA 薄膜和 Ag₂I₂ （dppb-Ac）₂ 的纯薄膜显示出明亮的蓝绿色和绿色发射，在 506 和 532 nm 处达到峰值，光致发光量子产率 （PLQY） 分别为 70% 和 52%，寿命分别为 18.9 和 7.9 μs。在已报道的基于 Ag（）的 TADF 发射器中，薄膜中 Ag₂I₂（dppb-Ac）₂ 的高 PLQY 和有效抑制的发射浓度猝灭非常出色。