Ultrafast Carrier and Lattice Dynamics in Plasmonic Nanocrystalline Copper Sulfide Films.
Ultrafast Carrier and Lattice Dynamics in Plasmonic Nanocrystalline Copper Sulfide Films.
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DOI：
10.1002/lpor.202000346
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发表时间：
2021-03
影响因子：
11
通讯作者：
Zayats AV
中科院分区：
文献类型：
--
作者：
Bykov AY;Shukla A;van Schilfgaarde M;Green MA;Zayats AV
等离子体纳米结构中的载流子激发动力学决定了许多重要的光学性质，如非线性光学响应和光催化活性。这里显示，具有低自由载流子浓度的介观等离子体铜蓝纳米晶体表现出比传统等离子体材料快得多的载流子弛豫。非平衡热载流子在光激发后的前20 fs内热化。与大块铜蓝相比，纳米晶体中的热化时间减少与在纳米薄膜中的库仑屏蔽减少一致。由于较低的载流子浓度，热化平衡电子气的随后弛豫比传统等离子体金属更快，并且与在表面态没有量子限制或热空穴捕获的证据的大块铜蓝中的弛豫很好地一致。还证明了铜蓝中相干光学声子模式的激发，揭示了等离子体材料中的相干晶格动力学，到目前为止，这主要限于金属，半导体和半金属。这些发现显示了这种新的介观等离子体材料的光学过程的主动控制的优势。等离子体纳米结构中的激发载流子动力学决定了许多重要的光学性质。本文报道了介观等离子体铜蓝石纳米晶体中平衡和非平衡热载流子动力学的全面研究，其表现出比传统等离子体材料快得多的载流子弛豫。此外，在等离子体材料的相干晶格动力学进行了演示和分析。
Excited carrier dynamics in plasmonic nanostructures determines many important optical properties such as nonlinear optical response and photocatalytic activity. Here it is shown that mesoscopic plasmonic covellite nanocrystals with low free‐carrier concentration exhibit a much faster carrier relaxation than in traditional plasmonic materials. A nonequilibrium hot‐carrier population thermalizes within first 20 fs after photoexcitation. A decreased thermalization time in nanocrystals compared to a bulk covellite is consistent with the reduced Coulomb screening in ultrathin films. The subsequent relaxation of thermalized, equilibrium electron gas is faster than in traditional plasmonic metals due to the lower carrier concentration and agrees well with that in a bulk covellite showing no evidence of quantum confinement or hot‐hole trapping at the surface states. The excitation of coherent optical phonon modes in a covellite is also demonstrated, revealing coherent lattice dynamics in plasmonic materials, which until now was mainly limited to dielectrics, semiconductors, and semimetals. These findings show advantages of this new mesoscopic plasmonic material for active control of optical processes. Excited carrier dynamics in plasmonic nanostructures determines many important optical properties. Here a comprehensive study of equilibrium and non‐equilibrium hot carrier dynamics in mesoscopic plasmonic covellite nanocrystals is reported, which exhibit a much faster carrier relaxation than traditional plasmonic materials. Furthermore, coherent lattice dynamics in plasmonic materials is demonstrated and analyzed.
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影响因子：
8.6
作者：
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通讯作者：
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影响因子：
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作者：
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通讯作者：
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影响因子：
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作者：
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