Photoluminescence enhancement of silicon quantum dot monolayer by plasmonic substrate fabricated by nano-imprint lithography

Abstract

Near-field coupling between a silicon quantum dot (Si-QD) monolayer and a plasmonic substrate fabricated by nano-imprint lithography and having broad multiple resonances in the near-infrared (NIR) window of biological substances was studied by precisely controlling the QDs-substrate distance. A strong enhancement of the NIR photoluminescence (PL) of Si-QDs was observed. Detailed analyses of the PL and PL excitation spectra, the PL decay dynamics, and the reflectance spectra revealed that both the excitation cross-sections and the emission rates are enhanced by the surface plasmon resonances, thanks to the broad multiple resonances of the plasmonic substrate, and that the relative contribution of the two enhancement processes depends strongly on the excitation wavelength. Under excitation by short wavelength photons (405 nm), where enhancement of the excitation cross-section is not expected, the maximum enhancement was obtained when the QDs-substrate distance was around 30 nm. On the other hand, under long wavelength excitation (641 nm), where strong excitation cross-section enhancement is expected, the largest enhancement was obtained when the distance was minimum (around 1 nm). The achievement of efficient excitation of NIR luminescence of Si-QDs by long wavelength photons paves the way for the development of Si-QD-based fluorescence bio-sensing devices with a high bound-to-free ratio.

Progress in Color Conversion Technology for Micro‐LED

“…Because currently in production process, there will be problems such as template processing that is heavily dependent on photolithography technology, nanoimprint primer problems, and alignment problems. Most importantly, the thickness of QD films prepared by nanoimprint method is mostly hundreds of nanometers, [158][159][160] which will cause serious light leakage as a CCL, thus limiting its development. It is believed that with the technological innovation and the improvement of the resolution of the chip, the research of this method in the CCL can be further expanded.…”

Gold nanopillar array with sharp surface plasmon resonances and the application in immunoassay

“…Figure 1(a) shows a schematic illustration of the process for the fabrication of a plasmonic substrate. 37 Polyolefin substrates with dome-shaped structures fabricated by nanoimprinting were purchased from SCIVAX (LP230/200-120). Figure 1(b) shows the scanning electron microscope (SEM) (FEI, HELIOS NANOLAB G3 UC) image of the nanoimprinted structure.…”

Mechanism of Corrosion Selectivity of NSb2Te Thin Films in the H3PO4/HNO3 Developer for Direct Laser Writing Nanolithography

“…Nanolithography, currently the most precise processing method, is widely applied for the microelectronic and optoelectronic device manufacturing. − Nanolithography can be categorized into mask lithography (such as photolithography , and nanoimprint lithography , ) and maskless direct writing lithography (involving electron beam, focused ion beam, scanning probe, and direct laser writing) based on the utilization of templates. Among others, direct laser writing has extensive applications in the fields of sensing, data storage, and micro-electromechanical systems due to its merits of low cost, high efficiency, simple operation, etc. − Unfortunately, high resolution is difficult to be realized via direct laser writing lithography due to the restriction of the optical diffraction limit .…”