Sensitivity improvement of Schottky-type plasmonic detector
Sensitivity improvement of Schottky-type plasmonic detector
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DOI：
10.1117/12.2033619
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发表时间：
2013-12
期刊：
影响因子：
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通讯作者：
A. Takeda;T. Aihara;M. Fukuhara;Y. Ishii;M. Fukuda
中科院分区：
文献类型：
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作者：
A. Takeda;T. Aihara;M. Fukuhara;Y. Ishii;M. Fukuda
表面等离子体激元(SPP)是由集体电子振荡组成的，这些电子振荡将纳米尺度的光能限制在超过衍射极限的范围内。SPP的这一优势促进了使用SPP的高密度光电集成电路(OEIC)的发展。肖特基等离子体探测器特别受到人们的关注，因为这些器件在通信波长范围内表现出灵敏度，并且可以以简单的制造工艺集成到硅基电子电路中。我们研制了一种具有纳米狭缝的Au/Si肖特基等离子体探测器，它能激发Au/Si界面上的表面等离子体激元。在这份报告中，我们展示了一种新的纳米狭缝布置，它为探测器提供了灵敏度改进。用时域有限差分法计算了Au/Si界面SPP模的最大电场强度，发现在Au/Si界面上放置两倍于SPP波长间距的狭缝可以产生最大的电场强度。利用这种狭缝间距，也证实了空气/Au界面上的SPP模强度较弱，而Au/Si界面上的SPP模强度较强。在探测器的Au膜上形成了不同狭缝间距的纳米狭缝，并测量了光电流与狭缝间距的关系。实验结果显示了与模拟结果相似的趋势。这种新颖的纳米缝隙结构可以为未来的高速数据处理应用提供一种高效的等离子体探测器。
A surface plasmon polariton (SPP) is composed of collective electron oscillations that confine optical energies in nanoscale beyond the diffraction limit. This advantage of SPPs has promoted the development of high-density optoelectronic integrated circuits (OEICs) using SPPs. Schottky-type plasmonic detectors have attracted particular attention, because these devices show sensitivity in the telecommunications wavelength range and can be integrated into Si-based electronic circuits with a simple fabrication process. We have developed an Au/Si Schottky-type plasmonic detector with nano slits that excites SPPs at the Au/Si interface. In this report, we demonstrate a novel nano-slit arrangement that provides a sensitivity improvement for the detector. Using the finite-difference time-domain method, we have shown that the highest electric field intensity in the SPP mode on the Au/Si interface is generated by positioning slits with twice the pitch of the SPP wavelength at the Au/Si interface. Using this slit pitch, a weaker SPP mode intensity on the air/Au interface and a stronger SPP mode intensity at the Au/Si interface have also been confirmed. Nano slits with different slit pitches were formed in the Au film of the detector, and the slit pitch dependence of the photocurrent was measured. The experimental results showed similar tendencies to the simulation results. This novel nano-slit arrangement can provide an efficient plasmonic detector for future high-speed data processing applications.