Plasmonic Au Array SERS Substrate with Optimized Thin Film Oxide Substrate Layer

Materials

DesalegnT. Debu¹  Faezeh Tork Ladani¹  JosephB. Herzog²  ZacharyT. Brawley²  StephenJ. Bauman²  AhmadA. Darweesh² 

[1] Department of Physics, University of Arkansas, 825 W. Dickson St., Fayetteville, Arkansas, AR 72701, USA;Microelectronics-Photonics Graduate Program, University of Arkansas, 731 W. Dickson St., Fayetteville, Arkansas, AR 72701, USA;

关键词: plasmonics;    thin film;    SERS;    computational electromagnetics;    nanowires;    nano-optics;    grating;    array;   

DOI  :  10.3390/ma11060942

来源: DOAJ

【 摘 要 】

This work studies the effect of a plasmonic array structure coupled with thin film oxide substrate layers on optical surface enhancement using a finite element method. Previous results have shown that as the nanowire spacing increases in the sub-100 nm range, enhancement decreases; however, this work improves upon previous results by extending the range above 100 nm. It also averages optical enhancement across the entire device surface rather than localized regions, which gives a more practical estimate of the sensor response. A significant finding is that in higher ranges, optical enhancement does not always decrease but instead has additional plasmonic modes at greater nanowire and spacing dimensions resonant with the period of the structure and the incident light wavelength, making it possible to optimize enhancement in more accessibly fabricated nanowire array structures. This work also studies surface enhancement to optimize the geometries of plasmonic wires and oxide substrate thickness. Periodic oscillations of surface enhancement are observed at specific oxide thicknesses. These results will help improve future research by providing optimized geometries for SERS molecular sensors.

【 授权许可】

Unknown