Understanding the Optical Properties of Au@Ag Bimetallic Nanoclusters through Time-Resolved and Nonlinear Spectroscopy
Understanding the Optical Properties of Au@Ag Bimetallic Nanoclusters through Time-Resolved and Nonlinear Spectroscopy
复制标题
DOI：
10.1021/acs.jpcc.8b06360
复制
发表时间：
2018-09
期刊：
影响因子：
--
通讯作者：
Rosina Ho-Wu;P. Sahu;Nancy Wu;Tiankai Chen;Carrie Yu;Jianping Xie;T. Goodson
中科院分区：
文献类型：
--
作者：
Rosina Ho-Wu;P. Sahu;Nancy Wu;Tiankai Chen;Carrie Yu;Jianping Xie;T. Goodson
与单金属 Au 或 Ag 纳米团簇相比，双金属 Au@Ag 纳米团簇已被证明具有独特的性能。在目前的工作中，通过稳态和时间分辨吸收和发射以及双光子吸收测量研究了三种双金属纳米团簇（Au15@Ag、Au18@Ag 和 Au25@Ag）的光学性质。纳米团簇由金核和交替的金-银-配体表面壳结构组成。我们观察到双金属 Au@Ag 纳米团簇的吸收和发射比纯 Au 纳米团簇有所增强；此外，发射是蓝移的。所有混合团簇都显示出令人印象深刻的双光子吸收系数，其中 Au25@Ag 的效果大大增强。通过时间分辨瞬态吸收和发射研究了Au@Ag纳米团簇的激发态动力学，结果表明双金属纳米团簇比Au纳米团簇具有更长的激发态寿命。具体来说，表面...
Bimetallic Au@Ag nanoclusters have been shown to possess unique properties compared to their monometallic Au or Ag nanoclusters. In the present work, the optical properties of three bimetallic nanoclusters, namely, Au15@Ag, Au18@Ag, and Au25@Ag have been investigated by steady-state and time-resolved absorption and emission and two-photon absorption measurements. The nanoclusters are composed of a gold core and an alternating Au–Ag–ligand surface shell structure. We observed that the absorption and emission of the bimetallic Au@Ag nanoclusters are enhanced compared to the pure Au nanoclusters; the emission is, additionally, blue shifted. All of the mixed clusters showed impressive two-photon absorption coefficients with Au25@Ag showing a largely enhanced effect. The excited state dynamics of the Au@Ag nanoclusters was studied by time-resolved transient absorption and emission, which show that the bimetallic nanoclusters have longer excited state lifetimes than the Au nanoclusters. Specifically, the surfac...