Compared with some precise nanofabrication methods, such as EBL and FIB, holographic lithography (HL) is a convenient way to fabricate periodic structures in a large area and with superb uniformity. In this work, we developed the deep UV HL with 266 nm laser to obtain structure with a periodicity between 100 nm to 1μm, which cannot be achieved by traditional photolithography. We further developed a strategy to fabricate hybrid periodical dimmer arrays by deep UV HL and lift-off process, followed by selectively surface functionalization. Thermal treatment was employed to as an effective approach to tune the gap size, which provides an additionally adjustable factor. By coating the substrate with gold and the obtained nanostructures with gold or silver, we have obtained periodic plasmonic structure with excellent figure of merit based on refractive index change and strong and uniform SER activity. Such a hybrid periodical dimmer arrays can be used as an effective plasmonics structure, and have potential application as a platform for high-efficiency surface- and bio- analysis.
By using Surface-Enhanced Raman Scattering, we studied the orientation of liquid crystal 5CB absorbed on nano-roughened Ag and Au electrodes. Our results firstly suggest that the orientation of LC 5CB absorbed on nano-roughened Ag electrode is different from that of Au electrode. This implies that the interaction between LC 5CB and Ag is different from the interaction between LC 5CB and Au. The conclusion is that the orientation of LC 5CB absorbed on nano-roughened Ag electrode is perpendicular, and the orientation of LC 5CB absorbed on nano-roughened Au electrode is more complicated, including parallel, perpendicular and tilted.