Efficient Surface Plasmon Polariton Excitation and Control over Outcoupling Mechanisms in Metal-Insulator-Metal Tunneling Junctions
Efficient Surface Plasmon Polariton Excitation and Control over Outcoupling Mechanisms in Metal-Insulator-Metal Tunneling Junctions
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DOI：
10.1002/advs.201900291
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发表时间：
2020-02-22
期刊：
影响因子：
15.1
通讯作者：
Nijhuis, Christian A.
中科院分区：
文献类型：
--
作者：
Makarenko, Ksenia S.;Hoang, Thanh Xuan;Nijhuis, Christian A.
表面等离子体激元(SPP)是集成到片上纳米电路中的可行候选者，允许访问高数据带宽和低能耗。金属-绝缘体-金属隧道结(MIM-TJ)最近被证明可以电激发和探测表面等离子体激元，然而，实验测量的效率和外耦合机制还不完全清楚。结果表明，MIM-TJ腔SPP模(MIM-SPP)可以通过三种途径耦合：(1)通过MIM-TJ界面上MIM-SPP的散射，(Ii)通过电极的模式耦合，在金属-电介质界面(Bound-SPP)处，以及(Iii)通过在MIM-TJ边缘的模式耦合，产生光子和Bound-SPP模。研究还表明，对于Al-AlOx-Cr-Au MIM-TJ玻璃，MIM-SPP模式通过任一电极(路径2)有效地耦合到结合SPP；这种输出耦合路径可以通过改变各自的电极厚度来选择性地开启和关闭。在MIM-TJ边缘的输出耦合(路径3)是有效的，并且对边缘地形敏感，而大多数光发射来自MIM-SPP模式(路径1)的粗糙度诱导的散射。采用任意粗糙度分布，证明了不同的粗糙度刻面可以将MIM-SPP的输出耦合效率提高到0.62%。这些结果为理解开发与cmos兼容的等离子体电路元件所需的地形参数铺平了道路。
Surface plasmon polaritons (SPPs) are viable candidates for integration into on-chip nano-circuitry that allow access to high data bandwidths and low energy consumption. Metal-insulator-metal tunneling junctions (MIM-TJs) have recently been shown to excite and detect SPPs electrically; however, experimentally measured efficiencies and outcoupling mechanisms are not fully understood. It is shown that the MIM-TJ cavity SPP mode (MIM-SPP) can outcouple via three pathways to i) photons via scattering of MIM-SPP at the MIM-TJ interfaces, ii) SPPs at the metal-dielectric interfaces (bound-SPPs) by mode coupling through the electrodes, and iii) photons and bound-SPP modes by mode coupling at the MIM-TJ edges. It is also shown that, for Al-AlOx-Cr-Au MIM-TJs on glass, the MIM-SPP mode outcouples efficiently to bound-SPPs through either electrode (pathway 2); this outcoupling pathway can be selectively turned on and off by changing the respective electrode thickness. Outcoupling at the MIM-TJ edges (pathway 3) is efficient and sensitive to the edge topography, whereas most light emission originates from roughness-induced scattering of the MIM-SPP mode (pathway 1). Using an arbitrary roughness profile, it is demonstrated that various roughness facets can raise MIM-SPP outcoupling efficiencies to 0.62%. These results pave the way for understanding the topographical parameters needed to develop CMOS-compatible plasmonic circuitry elements.