Sun Jiaxin, Xu Wenjie, Liu Yixiang, Sun Bin, Xiong Jie, Lian Yongfu, Lou Yanhui, Feng Lai
Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education, School of Chemistry and Materials Science, Heilongjiang University, Harbin 150080, China.
School of Energy, Soochow Institute for Energy and Materials InnovationS, Soochow University, Suzhou 215006, China.
Nanoscale. 2025 Jan 16;17(3):1449-1457. doi: 10.1039/d4nr03184a.
Carbon dots (CDs) have attracted significant research interest due to their great potential in optoelectronic applications. Although various CDs have been synthesized the "bottom-up" pathway, few studies have focused on understanding the origins of the structural and optical diversities of CDs. In this study, two benzenoid acids with a slight structural variation (, 9-oxo-9-fluorene-2,7-dicarboxylic acid (FR) and 4,4'-biphenyl dicarboxylic acid (BP)) are employed as precursors, yielding orange- and red-emissive CDs with quantum yields of 43.1% and 30.9%, respectively. A combined experimental and theoretical study reveals that the structural and optical diversities of the CDs originate from the structural variation of their precursors. Furthermore, we demonstrate that the light-emitting diodes (LEDs) based on the blended emissive layer of poly(-vinyl carbazole) (PVK) and the synthesized CDs display cyan and yellow lights, respectively, with moderate turn-on voltages of 4.0 and 4.5 V and maximum luminance values of 454 and 276 cd m. Such different optoelectronic performances could be attributed to the different energy-level alignments of CDs-FR and CDs-BP, relative to that of PVK. This study thus provides a typical example to understand the precursor-dependent diversities of CDs, which may contribute to the rational screening of precursors towards CDs with desirable optical/optoelectronic properties.
碳点（CDs）因其在光电应用中的巨大潜力而引起了广泛的研究兴趣。尽管已经通过“自下而上”的途径合成了各种碳点，但很少有研究专注于理解碳点结构和光学多样性的起源。在本研究中，使用两种结构略有变化的苯酸（9-氧代-9-芴-2,7-二羧酸（FR）和4,4'-联苯二甲酸（BP））作为前驱体，分别得到量子产率为43.1%和30.9%的橙色和红色发光碳点。实验与理论相结合的研究表明，碳点的结构和光学多样性源于其前驱体的结构变化。此外，我们证明基于聚（乙烯基咔唑）（PVK）和合成碳点的混合发光层的发光二极管（LED）分别显示出青色和黄色光，开启电压适中，分别为4.0和4.5 V，最大亮度值分别为454和276 cd m。这种不同的光电性能可归因于相对于PVK，CDs-FR和CDs-BP的不同能级排列。因此，本研究提供了一个典型例子来理解碳点前驱体依赖性的多样性，这可能有助于合理筛选具有理想光学/光电性质的碳点前驱体。
