Surface plasmon enhanced light emission from semiconductor materials

Articleinphysica status solidi (c) 5(9):2822--2824 · July 2008with20 Reads
DOI: 10.1002/pssc.200779287
Surface plasmon (SP) coupling technique was used to enhance light emissions from semiconductor nanocrystals with evaporated metal layers. We found that the SP coupling can increase the internal quantum efficiencies (IQE) of emission from CdSe-based nanocrystals regardless of the initial efficiencies. This suggests that this technique should be much effective for various materials that suffer from low quantum efficiencies. We also obtained 70-fold enhancement of emission from silicon nanocrystals in silicon dioxide. Obtained IQE value is 38
    • "However, most research was related to thin metallic film. Very few researches have dealt with the relationship between surface roughness and plasmoninduced photoluminescence (PL) enhancement, even though the roughness of the metallic surface should be a crucial factor for effectively manipulating the interaction between metallic and semiconducting materials in nanoscale devices121314151617181920. Therefore, in this paper, metallic Ag nanoneedle films were used for observing luminescence enhancement depending on surface roughness. "
    [Show abstract] [Hide abstract] ABSTRACT: Noble metal nanostructure allows us to tune optical and electrical properties, which has high utility for real-world application. We studied surface plasmon-induced emission of semiconductor quantum dots (QDs) on engineered metallic nanostructures. Highly passive organic ZnS-capped CdSe QDs were spin-coated on poly-(methyl methacrylate)-covered Ag films, which brought QDs near the metallic surface. We obtained the enhanced electromagnetic field and reduced fluorescence lifetimes from CdSe/ZnS QDs due to the strong coupling of emitter wave function with the Ag plasmon resonance. Observed changes include a six-fold increase in the fluorescence intensity and striking reduction in fluorescence lifetimes of CdSe/ZnS QDs on rough Ag nanoneedle compared to the case of smooth surfaces. The advantages of using those nanocomposites are expected for high-efficiency light-emitting diodes, platform fabrication of biological and environmental monitoring, and high-contrast imaging.
    Full-text · Article · Aug 2012
    • "It has been shown that close proximity to surface plasmon polaritons (SPPs) on surfaces and localized surface plasmons (SPs) in nanoparticles can strongly enhance observed emission intensity for fluorescent materials [4]. The use of nanoparticles as mediators for enhanced fluorescence has been studied extensively in recent years and many results have been published demonstrating that high enhancements can be obtained by placing fluorophores in close proximity to these SPPs or SPs[4] [5] [6] [7] [8] [9] [10] [11] [12]. Previous work from our group has established that it is also possible to obtain strong enhancement of emission from fluorescent dyes by using planar gold films coated in PMMA, which is then patterned by electron beam lithography to produce linear gratings to facilitate coupling to SPPs "
    [Show abstract] [Hide abstract] ABSTRACT: We experimentally demonstrate the enhancement of fluorescence from quantum dots excited by interaction with surface plasmon polaritons on nanostructured metal surfaces. The relationship between observed enhancement and geometrical factors of the surface structure has been used to explore the behavior of quantum dots on different substrates. Imaging using standard fluorescence optical microscopy clearly demonstrates a strong dependence of fluorescence enhancement on fundamental parameters for periodic surface structures.
    Full-text · Article · Mar 2010
    • "d similar obvious enhancements of both PL intensities and emission rates for several materials , such as organic dye molecules doped in polymers [41], light-emitting polymer with π-electron conjugation [42], and CdSe-based quantum dot nanocrystals [43] . Moreover, we obtained a large PL enhancement for silicon nanocrystals in silicon dioxide media. [44] Usually, the emission efficiencies of such indirect semiconductors are quite low, but by using the SP coupling , it is possible to increase these efficiencies up to values as large as those of direct compound semiconductors. We believe that the SP coupling technique would provide extremely bright silicon-based light-emitting devices, wh"
    [Show abstract] [Hide abstract] ABSTRACT: We report novel methods to enhance light emission efficiencies from InGaN/GaN quantum wells (QWs) based on nanophotonics and plasmonics. First, the nanoscopic optical properties were observed and characterized based on the carrier localization and the quantum confinement Stark effect depending on the In composition of InGaN. Based on the results, we proposed that the emission efficiencies should be improved by making nanostructures, and showed actual enhancement of photoluminescence (PL) intensities by using fabricated random nanodisk and arrayed nanopillar structures. Moreover, surface plasmon (SP) coupling technique was used to enhance blue and green light emissions from InGaN/GaN QWs. We obtained a 14-fold increase in the PL intensity along with a 7-fold increase in the internal quantum efficiency (IQE) of light emission from InGaN/GaN when nanostructured Ag layers were deposited 10 nm above the QWs. The possible enhancement mechanism was discussed and reproduced by using the 3-D finite-difference time-domain simulations. Electron-hole pairs in InGaN QWs couple to electron oscillations at the metal surface and produce SPs instead of photons or phonons. This new path increases the spontaneous emission rate and the IQEs. The SP-emitter coupling technique would lead to superbright and high-speed solid-state light-emitting devices that offer realistic alternatives to conventional fluorescent light sources.
    Article · Sep 2009
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