The development of single-system materials that exhibit both multicolor room-temperature phosphorescence (RTP) and thermally activated delayed fluorescence (TADF) with tunable after glow colors and channels is challenging. In this study, four metal-free carbon dots (CDs) are developed through structural tailoring, and panchromatic high-brightness RTP is achieved via strong chemical encapsulation in urea. The maximum lifetime and quantum yield reaches 2141 ms and 56.55%, respectively. Moreover, CDs-IV@urea, prepared via coreshell interaction engineering, exhibits a dual afterglow of red RTP and green TADF. The degree of conjugation and functional groups of precursors affects the binding interactions of the nitrogen cladding on CDs, which in turn stabilizes triplet energy levels and affects the energy gap between S₁ and T₁ (ΔE_ST) to induce multicolor RTP. The enhanced wrapping interaction lowers the ΔE_ST, promoting reverse intersystem crossing, which leads to phosphorescence and TADF. This strong coreshell interaction fully stabilizes the triplet state, thus stabilizing the material in water, even in extreme environments such as strong acids and oxidants. These afterglow materials are tested in multicolor, time, and temperature multiencryption as well as in multicolor in vivo bioimaging. Hence, these materials have promising practical applications in information security as well as biomedical diagnosis and treatment.

中文翻译：

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具有意外热激活延迟荧光的全色超稳定室温磷光碳点复合材料的定制制造

开发同时具有多色室温磷光（RTP）和热激活延迟荧光（TADF）且后发光颜色和通道可调的单系统材料具有挑战性。在这项研究中，通过结构定制开发了四种无金属碳点（CD），并通过尿素中的强化学封装实现了全色高亮度RTP。最大寿命和量子产率分别达到2141 ms和56.55%。此外，通过核壳相互作用工程制备的CDs-IV@urea表现出红色RTP和绿色TADF的双重余辉。前体的共轭程度和官能团影响碳点上氮包层的结合相互作用，进而稳定三线态能级并影响S ₁和T ₁之间的能隙(Δ E _ST )以诱导多色RTP。增强的包裹相互作用降低了 Δ E _ST，促进反向系间窜越，从而产生磷光和 TADF。这种强核壳相互作用完全稳定了三重态，从而使材料在水中稳定，即使在强酸和氧化剂等极端环境下也是如此。这些余辉材料经过多色、时间和温度多重加密以及多色体内生物成像测试。因此，这些材料在信息安全以及生物医学诊断和治疗方面具有广阔的实际应用前景。