Site-Selective Plasmonic Etching of Silver Nanocubes
Site-Selective Plasmonic Etching of Silver Nanocubes
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DOI：
10.1021/acs.jpclett.6b02393
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发表时间：
2016-11-03
影响因子：
5.7
通讯作者：
Tatsuma, Tetsu
中科院分区：
文献类型：
--
作者：
Saito, Koichiro;Tanabe, Ichiro;Tatsuma, Tetsu
等离激元纳米颗粒和半导体之间界面的等离激元诱导电荷分离（PIGS）现已广泛用于光伏和光催化。在这里，我们利用 PIGS 对 TiO2 上的银纳米立方体进行位点选择性纳米蚀刻，超出衍射极限。当银纳米立方体放置在 TiO2 上时，它会表现出两种位于纳米立方体顶部和底部的共振模式（分别为远端模式和近端模式）。我们分别基于远端和近端模式通过 PIGS 实现了纳米立方体顶部和底部的选择性蚀刻。位点选择性纳米光子刻蚀揭示了PIGS中涉及的阳极反应是由等离子体近场引起的，从而引起外部光电效应。特别是，顶部边缘的远端模式蚀刻可以用高能电子（或热电子）从远端位置穿过纳米立方体喷射到 TiO2 来解释。
Plasmon-induced charge separation (PIGS) at the interface between a plasmonic nanoparticle and semiconductor is now widely used for photovoltaics and photocatalysis. Here we take advantage of PIGS for site-selective nanoetching of silver nanocubes on TiO2 beyond the diffraction limit. A silver nanocube exhibits two resonance modes localized at the top and bottom of the nanocube (distal and proximal modes, respectively) when it is placed on TiO2. We achieved selective etching at the top and the bottom of the nanocubes by PIGS based on the distal and proximal modes, respectively. The site-selective nanophotonic etching reveals that the anodic reaction involved in PIGS is induced by the plasmonic near field, which causes an external photoelectric effect. In particular, the distal mode etching at the top edges is explained in terms of ejection of energetic electrons (or hot electrons) from the distal site to TiO2 across the nanocube.