Chavarin C A, Hardt E, Gruessing S, Skibitzki O, Costina I, Spirito D, Seifert W, Klesse W, Manganelli C L, You C, Flesch J, Piehler J, Missori M, Baldassarre L, Witzigmann B, Capellini G
Opt Express. 2021 Mar 1;29(5):7680-7689. doi: 10.1364/OE.418382.
Ge-on-Si plasmonics holds the promise for compact and low-cost solutions in the manipulation of THz radiation. We discuss here the plasmonic properties of doped Ge bow-tie antennas made with a low-point cost CMOS mainstream technology. These antennas display resonances between 500 and 700 GHz, probed by THz time domain spectroscopy. We show surface functionalization of the antennas with a thin layer of α-lipoic acid that red-shifts the antenna resonances by about 20 GHz. Moreover, we show that antennas protected with a silicon nitride cap layer exhibit a comparable red-shift when covered with the biolayer. This suggests that the electromagnetic fields at the hotspot extend well beyond the cap layer, enabling the possibility to use the antennas with an improved protection of the plasmonic material in conjunction with microfluidics.
锗硅等离子体激元学有望为太赫兹辐射的操控提供紧凑且低成本的解决方案。我们在此讨论采用低成本互补金属氧化物半导体主流技术制造的掺杂锗蝴蝶结天线的等离子体激元特性。这些天线在500至700吉赫兹之间显示出共振，通过太赫兹时域光谱法进行探测。我们展示了用一层薄的α-硫辛酸对天线进行表面功能化处理，这使天线共振发生约20吉赫兹的红移。此外，我们表明，用氮化硅帽层保护的天线在覆盖生物层时也会出现类似的红移。这表明热点处的电磁场延伸到帽层之外，使得在微流体结合使用时能够在更好地保护等离子体激元材料的情况下使用这些天线成为可能。
