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研究了半导体纳米粒子(SNPs)-金属纳米颗粒(MNPs)耦合导致的SNPs的发光强度猝灭和荧光寿命增强潜在的物理机制,并用传统F?ster共振能量传递(FRET)理论描述和分析实验结果。光致发光光谱(PL)和时间分辨光谱观测表明,SNPs的PL强度发生了明显的猝灭,荧光寿命从17.7 ns到30.8 ns延长了近2倍。这种杂化纳米结构表现出不同于杂化前各独立组分的新的协同相互作用光学性质。胶体化学使杂化SNP_SMNP纳米结构中SNP_S和MNP构成一个新的单元称为等离激子激元(Plexciton)或激子等离子激元(Excimon),这已在一系列杂化结构中被确认。基于泵浦-探测技术的飞秒瞬态吸收(TA)的实验结果证实了这种从激子-等离激元到等离激子的转换。实验结果分析表明,传统F?ster共振能量传递理论不能很好地描述实验结果,在金属存在的情况下,还需要对该理论进一步调整和改进。
The potential physical mechanism of luminescence intensity quenching and fluorescence lifetime enhancement of SNPs caused by the coupling of semiconductor nanoparticles (SNPs) and metal nanoparticles (MNPs) was studied. The experimental results were described and analyzed by using the traditional F? Res resonance energy transfer (FRET) theory . The photoluminescence (PL) and time resolved spectroscopy observations showed that the PL intensity of SNPs quenched significantly, and the fluorescence lifetime was nearly doubled from 17.7 ns to 30.8 ns. This hybrid nanostructure exhibits new synergistic interaction optical properties that are different from the individual components prior to hybridization. Colloidal chemistry makes SNP_S and MNP in hybrid SNP_SMNP nanostructures constitute a new unit called Plexciton or Excimon, which has been identified in a series of hybrid structures. Experimental results based on pump-probe femtosecond transient absorption (TA) confirm this shift from exciton-plasmonic to plasmon excitons. Experimental results show that the traditional F? Ster resonance energy transfer theory can not describe the experimental results well. In the presence of metal, the theory needs to be further adjusted and improved.