Bonding state energy of metal nanoparticle dimer and its dependence on nanosphere size and interparticle separation
Bonding state energy of metal nanoparticle dimer and its dependence on nanosphere size and interparticle separation
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DOI：
10.1142/s0218863518500182
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发表时间：
2018-06
影响因子：
2.7
通讯作者：
M. V. Stephanie;A. Iskandar;M. Tjia
中科院分区：
文献类型：
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作者：
M. V. Stephanie;A. Iskandar;M. Tjia
进行了一项关于粒径[公式：见正文]和粒子间分离[公式：见正文]对两个相同金属纳米球的二聚体中电磁（等离子体）耦合的影响的研究。二聚体状态被建模为两个孤立的等离子体激元状态的杂化成键和反键状态，其中相关能量以组成等离子体激元场的孤立等离子体激元能量（[公式：见正文]）、耦合能量（[公式：见正文]）和重叠积分（[公式：见正文]）的形式给出。根据Mie理论，计算了平行偏振光沿着二聚体轴入射时，孤立等离子体激元和二聚体在一定介质中的共振吸收能。结果与Au和Ag纳米球二聚体的键合状态能量拟合，[式：见正文]范围在10-20[式：见正文]nm内，x在[式：见正文]-200[式：见正文]nm内变化，符合偶极吸收光谱的限制性考虑。键合态能量[式：见正文]对于[式：见正文]和[式：见正文]变化范围的极好拟合通过[式：见正文]形式的单一函数在[式：见正文]约0.99的情况下一致地实现，其中[式：见正文]和[式：见正文]随所考虑的纳米球材料和周围介质而变化。这一结果表明了最佳拟合函数形式[公式：见正文]与潜在物理机制的可能关系。
A study is conducted regarding the effects of particle size [Formula: see text] and interparticle separation [Formula: see text] on the electromagnetic (plasmon) coupling in a dimer of two identical metal nanospheres. The dimer states are modeled as the hybridized bonding and antibonding states of two isolated plasmon states, with the associated energies given in terms of the isolated plasmon energy ([Formula: see text], the coupling energy ([Formula: see text] and the overlap integral ([Formula: see text] of the constituent plasmonic fields. The resonance absorption energies of the isolated plasmon and the dimer in certain dielectric medium are calculated according to the Mie theory for incident light of parallel polarization along the dimer axis. The results are fitted with the bonding state energies of both Au and Ag nanosphere dimers for [Formula: see text] ranging within 10–20[Formula: see text]nm and x varied within [Formula: see text]–200[Formula: see text]nm in compliance with the restricted consideration of dipole absorption spectra. The excellent fits of the bonding state energies [Formula: see text] for the ranges of [Formula: see text] and [Formula: see text] variations are consistently achieved with [Formula: see text] around 0.99 by a single function of the form [Formula: see text] where [Formula: see text] and [Formula: see text] vary with the nanosphere materials and the surrounding media considered. This result suggests the possible relation of the best fitted functional form [Formula: see text] with the underlying physical mechanism.