Department of Chemistry, Yonsei University, Seoul, 03722, Republic of Korea.
Department of Chemistry, Western Michigan University, Kalamazoo, MI, 49008, USA.
Small. 2021 Jul;17(27):e2004836. doi: 10.1002/smll.202004836. Epub 2021 Feb 9.
The development of efficient light-harvesting systems is important to understand the key aspects of solar-energy conversion processes and to utilize them in various photonic applications. Here, atomically well-defined gold nanoclusters are reported as a new platform to fabricate artificial light-harvesting systems. An efficient amide coupling method is developed to synthesize water-soluble Au clusters fully protected with pyrene chromophores by taking advantage of their facile phase-transfer reaction. The synthesized Au clusters with densely packed 18 pyrene chromophores (Au -PyB ) exhibit triple-emission in blue, green, and red wavelength regions arising respectively from pyrene monomer, pyrene excimer, and Au emission, producing bright white light emission together. The photoluminescence of Au is enhanced by more than tenfold, demonstrating that pyrenes at the periphery efficiently channel the absorbed energy to the luminescent Au at the center. A combination of femtosecond transient absorption and anisotropy measurements of Au -PyB explicitly reveals three main decay components of 220 fs, 3.5 ps, and 160 ps that can be assigned to energy migration between pyrenes and energy transfer processes from pyrene monomer and excimer to the central Au , respectively.
高效的光收集系统的发展对于理解太阳能转换过程的关键方面以及将其应用于各种光子学应用非常重要。在这里，原子定义明确的金纳米团簇被报道为制造人工光收集系统的新平台。开发了一种有效的酰胺偶联方法，利用其易于进行的相转移反应，以合成完全由芘发色团保护的水溶性 Au 团簇。合成的具有密集排列的 18 个芘发色团（Au-PyB）的 Au 团簇在蓝色、绿色和红色波长区域分别表现出来自芘单体、芘激基复合物和 Au 发射的三重发射，产生明亮的白色发射。Au 的光致发光增强了十倍以上，证明了外围的芘能够有效地将吸收的能量传递到中心的发光 Au。飞秒瞬态吸收和 Au-PyB 的各向异性测量的组合明确揭示了三个主要的衰减分量，分别为 220 fs、3.5 ps 和 160 ps，它们可以分别分配给芘之间的能量迁移以及从芘单体和激基复合物到中心 Au 的能量转移过程。
