Enhancement of Radiative Plasmon Decay by Hot Electron Tunneling.
Enhancement of Radiative Plasmon Decay by Hot Electron Tunneling.
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DOI：
10.1021/acsnano.5b02361
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发表时间：
2015-07
期刊：
影响因子：
17.1
通讯作者：
Xiao Wang;K. Braun;Dai Zhang;H. Peisert;H. Adler;T. Chassé;A. Meixner
中科院分区：
文献类型：
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作者：
Xiao Wang;K. Braun;Dai Zhang;H. Peisert;H. Adler;T. Chassé;A. Meixner
在这里，我们证明，通过使用平行于尖端轴（即垂直于样品）的电场分量的 634 nm 激光照射结，可以显着增强通过尖锐 Au 尖端和 Au 基板之间的纳米单间隙的非弹性隧道效应引起的光子发射。分析作为偏压函数记录的光致发光 (PL) 光谱，使我们能够区分 PL 和 (1) 由激光激发 sp/d 带间跃迁（特征带为 690 nm）产生的电子空穴对的衰变，以及 (2) 由间隙形成的特征等离激元模式的红移辐射衰变。由于电致发光光谱（无激光）已经显示出等离子体间隙模式，因此我们得出结论，激光照射引起的强度增强源自费米能级之上的热电子通过非弹性隧道效应和光子发射到等离子体模式的辐射衰变。由于这些过程可以通过激光照明和偏置电压的幅度独立控制，因此设计新型可切换光子发射等离子体器件具有很大的意义。
Here we demonstrate that photon emission induced by inelastic tunneling through a nanometer single gap between a sharp Au tip and an Au substrate can be significantly enhanced by the illumination of the junction with 634 nm laser light with an electric field component oriented parallel to the tip-axis, i.e., perpendicular to the sample. Analyzing photoluminescence (PL) spectra recorded as a function of bias voltage allows us to distinguish between PL from (1) the decay of electron-hole pairs created by the laser excited sp/d interband transition with a characteristic band at 690 nm and (2) the red-shifted radiative decay of characteristic plasmon modes formed by the gap. Since the electroluminescence spectra (without laser) already show the plasmonic gap modes, we conclude that the enhanced intensity induced by laser illumination originates from the radiative decay of hot electrons closely above the Fermi level via inelastic tunneling and photon emission into the plasmon modes. Since these processes can be independently controlled by laser illumination and the amplitude of the bias voltage, it is of great interest for designing new switchable photon emission plasmonic devices.