Two UV plasmonic devices by high-performance epitaxial Al metasurfaces - an ultrasensitive photodetector and a surface-enhanced resonance Raman spectroscopic (SERRS) biosensor

Ta-Jen Yen^1*, Abhishek Dubey¹, Shangjr Gwo³

¹Department of Material Sciences and Engineering, National Tsing Hua University, Hsinchu, Taiwan
²2Institute of Nanoengineering and Microsystem, National Tsing Hua University, Hsinchu, Taiwan
³3Department of Physics, National Tsing Hua University, Hsinchu, Taiwan

* Presenter:Ta-Jen Yen, email:tjyen@mx.nthu.edu.tw

Plasmonics-based devices have been intensively explored in visible and infrared regimes, but scarcely demonstrated in the wide UV regime, mainly because of constrained optical properties of materials. By using epitaxial Al metasurfaces, herein we report two unprecedented plasmonic applications in UV regimes- an ultrasensitive photodetector and a surface-enhanced resonance Raman spectroscopic (SERRS) biosensor. For the first UV plasmonic device, we demonstrated ultrasensitive photodetector with a maximum detectivity (1.48 × 1015 cm Hz1/2 W-1) at the on-resonance wavelength of 355 nm. broad bandwidth photodetection through the entire UV regime, and a fast temporal response with a rise time of 51 ms and a fall time of 197 ms, respectively. For the second UV plasmonic device, we presented an SERRS biosensor. Such a UV SERRS biosensor not only exhibited high signal to noise ratios, but also recorded an SERRS enhancement factor up to 106 for extremely thin layer of adenine of 1nm thick. In addition to this egregiously high EF factor, we further exhibit that our SERRS substrate is capable of detecting the single base mutation in the 12-mer ss-DNA.

Keywords: plasmonics, SERRS, UV photodetector