Enhanced Radiative Emission Rate and Quantum Efficiency in Coupled Silicon Nanocrystal-Nanostructured Gold Emitters

Abstract

i Biteen, et al., Enhanced radiative emission rate and quantum efficiency… SUPPORTING INFORMATION:The nanoporous gold (np-Au) film was characterized optically with a Sentech SE-850 spectroscopic ellipsometer. Transmission and reflection spectra were used to calculate the absorbance spectrum, and spectroscopic ellipsometry confirmed that the film's thickness was 150 nm. These measurements were used to derive the extinction cross section spectrum in Figure 1 (red line), assuming, based on SEM data, that the average np-Au particle in the 50% Au/50% air film is a sphere of radius 10 nm. A 150-nm thick film of continuous Au deposited on SiO 2 by evaporation was also studied with the Sentech SE-850, and its transmission and reflection spectra were used to determine its absorbance spectrum. The np-Au film has a broad extinction spectrum that shows a peak between 300 and 400 nm, and a tail that decreases with increasing wavelength through most of the visible. Though the absorbance cross sections of both np-and bulk Au peak at similar wavelengths, the percent absorbance of np-Au is more than 2.5 times that of planar bulk Au throughout the visible, and np-Au absorbs over a broader wavelength range than bulk Au. Indeed, we found for nc-Si in SiO 2 coupled to a planar, continuous film of bulk Au that the luminescence intensity was decreased at all separation distances, relative to a reference sample. 1 According to Mie-Gans theory 2 , the measured np-Au extinction cross section in Figure 1 is consistent with the aggregate surface plasmon resonant response for a continuum of features including Au spheres and spheroids in air and spherical and spheroidal voids in gold.

Enhanced quantum dot emission for luminescent solar concentrators using plasmonic interaction

“…This could be explained by increased absorption and enhanced emission rate of the QDs. It is known that emission enhancement occurs when the MNP surface plasmon resonance wavelength coincides with the emitter emission band [36][37][38]. Here, the broad SPR wavelength of the Au NPs has some overlap with the emission band of the QDs as shown in Fig.…”

“…The maximum enhancement occurs when the NP plasmon resonance wavelength coincides with the QD absorption band [33][34][35]. The second effect involves an increase in the fluorescence quantum yield of the optical emitter and is maximized when the MNPs resonance wavelength coincides with the QD emission band [36][37][38]. The total fluorescence emission rate is given by [32] …”

Simulation and Optimization of Nonperiodic Plasmonic Nano-Particles

“…Recently there has been a growing interest in plasmonic nanoparticles. They have strong effects on light in the visible and invisible regions of the photonic spectrum for applications such as Raman scattering [4], radiative rate enhancement [5], solar cells [6], and optical biosensors [7]. Since the optical properties of these particles depend on their sizes and shapes, one of the desired goals is to control the shapes of metal and semiconductor nanoparticles.…”

Strain-driven alignment of In nanocrystals on InGaAs quantum dot arrays and coupled plasmon-quantum dot emission

“…1-3 More recently, the coupling of a QD to the plasmon resonance of a metal nanoparticle or nanoparticle array has attracted much attention, representing the ultimate electromagnetic resonator with subwavelength size. Such hybrid QD-metal nanoparticle structures enable the enhancement of the QD emission, [4][5][6][7] control of the polarization of emitted light, 8 modification of the far field radiation pattern, 9 and other interesting collective optical phenomena. 10,11 So far, fabricating those structures relied on chemical self-assembly 12 or top-down processing, 8 the latter being without control of the position of the QDs with respect to the metal nanostructures which is required to fully exploit their unique properties.…”