As an emerging building unit, carbon dots (CDs) have been igniting the revolutionaries in the fields of optoelectronics, biomedicine, and bioimaging. However, the difficulty of synthesizing CDs in aqueous solution with full‐spectrum emission severely hinders further investigation of their emission mechanism and their extensive applications in white light emitting diodes (LEDs). Here, the full‐color‐emission CDs with a unique structure consisting of sp³‐hybridized carbon cores with small domains of partially sp²‐hybridized carbon atoms are reported. First‐principle calculations are initially used to predict that the transformation from sp³ to sp² hybridization redshifts the emission of CDs. Guided by the theoretical predictions, a simple, convenient, and controllable route to hydrothermally prepare CDs in a single reaction system is developed. The prepared CDs have full‐spectrum emission with an unprecedented two‐photon emission across the whole visible color range. These full‐color‐emission CDs can be further nurtured by slight modifications of the reaction conditions (e.g., temperature, pH) to generate the emission color from blue to red. Finally a flexible LEDs with full‐color emission by using epoxy CDs films is developed, indicating that the strategy affords an industry translational potential over traditional fluorophores.

中文翻译：

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水热单反应体系中多色发射碳点的合理设计

作为一种新兴的建筑单元，碳点（CD）一直在光电、生物医学和生物成像领域引发革命。然而，在水溶液中合成全光谱发射的CD的困难严重阻碍了对其发射机制的进一步研究及其在白光发光二极管（LED）中的广泛应用。在这里，报道了具有独特结构的全色发射CD，该结构由sp ³杂化碳核和部分sp ^{2杂化碳原子的小域组成。}第一原理计算最初用于预测从sp ^{3 杂交}到sp ²杂交的转变会导致 CD 的发射发生红移。在理论预测的指导下，开发了一种简单、方便、可控的在单一反应体系中水热制备CD的路线。所制备的 CD 具有全光谱发射，在整个可见颜色范围内具有前所未有的双光子发射。这些全色发射 CD 可以通过稍微修改反应条件（例如温度、pH）来进一步培育，以产生从蓝色到红色的发射颜色。最后，使用环氧 CD 薄膜开发出具有全色发光的柔性 LED，这表明该策略比传统荧光团具有行业转化潜力。