Observation of laser oscillation in aggregates of ultrasmall silicon nanoparticles

Nayfeh, Munir H.; Rao, Satish; Barry, Nicolas P. E.; Therrien, Joel; Belomoin, G.; Smith, Audrey; Chaı̈eb, Sahraoui

doi:10.1063/1.1428622

Cited by 115 publications

(52 citation statements)

References 21 publications

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“…[1][2][3][4] The emission bands of these Si-SiO 2 composites have been studied as a function of silicon excess for materials obtained from different fabrication methods. 5,6 The emission band coming from Si nanocrystals embedded in SiO 2 appears after Si excess precipitation into nanocrystals during a high-temperature annealing and it peaks between 1.4 and 1.7 eV.…”

Section: Introductionmentioning

confidence: 99%

Optical-geometrical effects on the photoluminescence spectra of Si nanocrystals embedded in SiO2

Ferré

Garrido

Pellegrino

et al. 2005

Journal of Applied Physics

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We demonstrate that thickness, optical constants, and details of the multilayer stack, together with the detection setting, strongly influence the photoluminescence spectra of Si nanocrystals embedded in SiO 2 . Due to multiple reflections of the visible light against the opaque silicon substrate, an interference pattern is built inside the oxide layer, which is responsible for the modifications in the measured spectra. This interference effect is complicated by the depth dependence of ͑i͒ the intensity of the excitation laser and ͑ii͒ the concentration of the emitting nanocrystals. These variations can give rise to apparent features in the recorded spectra, such as peak shifts, satellite shoulders, and even splittings, which can be mistaken as intrinsic material features. Thus, they can give rise to an erroneous attribution of optical bands or estimate of the average particle size, while they are only optical-geometrical artifacts. We have analyzed these effects as a function of material composition ͑Si excess fraction͒ and thickness, and also evaluated how the geometry of the detection setup affects the measurements. To correct the experimental photoluminescence spectra and extract the true spectral shape of the emission from Si nanocrystals, we have developed an algorithm based on a modulation function, which depends on both the multilayer sequence and the experimental configuration. This procedure can be easily extended to other heterogeneous systems.

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Section: Introductionmentioning

confidence: 99%

Optical-geometrical effects on the photoluminescence spectra of Si nanocrystals embedded in SiO2

Ferré

Garrido

Pellegrino

et al. 2005

Journal of Applied Physics

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“…A photo of a Si colloid excited by 355 nm radiation. such as laser oscillation [9] and second harmonic genera tion [10] in the visible part of the spectrum.…”

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confidence: 99%

“…The process involves gradual immersion of the wafer into a bath of HF and H 2 0 2 while arranging for an clectrical current to sk im the top skin of the wafer [7][8][9][10]. H 2 0 2 cata lizes the etching producing ultrasmall structu res and cleans impurities and produces a higher electron ic and chemical quality with an ideal hydrogen termination.…”

mentioning

confidence: 99%

Fluorescent Si nanoparticle-based electrode for sensing biomedical substances

Wang

Yau

Mantey

et al. 2008

Optics Communications

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“…Therefore, the ability to use silicon as the light-emitting diode material would potentially make optoelectronic device fabrication much easier, and is a focus of much silicon nanomaterial research. [10][11][12][13]44 Difficulties involved with integration of nanocrystalline Si into commercial devices arise in stabilizing the PL intensity and energy in aqueous or aerobic environments. 23,41,45 Changes in the PL of nanocrystalline Si over time, presumably alongside alterations in the surface chemistry or size of the particles, have been reported consistently across the literature.…”

Section: Technological Developments Leading To Photoluminescent Siliconmentioning

confidence: 99%

“…[6][7][8][9] The size-dependence of the optical properties of Si on the nanometer length scale heighten the potential for the development of all Si-based optoelectronic devices in which signals would be transferred by photopulses (i.e., light) generated by the nanocrystalline Si diodes. [10][11][12][13] Currently, the development of this type of technology is largely limited by the low efficiency and instability of the PL of Si nanomaterials. This low efficiency is thought to be caused in part by a variety of electronically active energy states belonging to defects that develop on the Si surface, the presence of which are expected to reduce the yield of radiative interband transitions.…”

Section: General Introductionmentioning

confidence: 99%

Investigation into Effects of Instability and Reactivity of Hydride-Passivated Silicon Nanoparticles on Interband Photoluminescence

Radlinger¹

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While silicon has long been utilized for its electronic properties, its use as an optical material has largely been limited due to the poor efficiency of interband transitions. However, discovery of visible photoluminescence (PL) from nanocrystalline silicon in 1990 triggered many ensuing research efforts to optimize PL from nanocrystalline silicon for optical applications. Currently, use of photoluminescent silicon nanoparticles (Si NPs) is commercially limited by: 1) the instability of the energy and intensity of the PL, and 2) the low quantum yield of interband PL from Si NPs.Herein, red-emitting, hydrogen-passivated silicon nanoparticles (H-Si NPs) were synthesized by thermally-induced disproportionation of a HSiCl 3 -derived (HSiO 1.5 )n polymer. The H-Si NPs produced by this method were then subjected to various chemical and physical environments to assess the long-term stability of the optical properties as a function of changing surface composition. This dissertation is intended to elucidate correlations between the reported PL instability and the observed changes in the Si NP surface chemistry over time and as a function of environment.First, the stability of the H-Si NP surface at slightly elevated temperatures towards reactivity with a simple alkane was probed. The H-Si NPs were observed by FT-IR spectroscopy to undergo partial hydrosilylation upon heating in refluxing hexane, in addition to varying degrees of surface oxidation. The unexpected reactivity of the Si surface in n-hexane supports the unstable nature of the H-Si NP surface, and furthermore implicates the presence of highly-reactive Si radicals on the surfaces of the Si NPs. We propose that reaction of alkene impurities with the Si surface radicals is largely responsible for the observed surface alkylation. However, we also present an alternate ii mechanism by which Si surface radicals could react with alkanes to result in alkylation of the surface.Next, the energy and intensity stability of the interband PL from H-Si NPs in the presence of a radical trap was probed. Upon addition of (2,2,6,6,-tetramethyl-piperidin-1-yl)oxyl (TEMPO), the energy and intensity of the interband transition was observed to change over time, dependent on the reaction conditions. First, when the reaction occurred at 4ºC with minimal light exposure, the interband transition exhibited a gradual hypsochromic shift to between 595 nm and 655 nm, versus the λ max of the original low energy emission peak at 700 nm, depending on the amount of TEMPO in the sample.Second, when the reaction proceeded at room temperature with frequent exposure to 360 nm irradiation, the original interband transition at 660 nm was quenched while a new peak at 575 nm developed. Based on all the data collected and analyzed, we assign the 595 -655 nm transition as due to interband exciton recombination from Si NPs with reduced diameters relative to the original Si NPs. We furthermore assign the 575 nm transition as due to an oxide-related defect state resulting from rapid oxidation of pho...

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Observation of laser oscillation in aggregates of ultrasmall silicon nanoparticles

Cited by 115 publications

References 21 publications

Optical-geometrical effects on the photoluminescence spectra of Si nanocrystals embedded in SiO2

Optical-geometrical effects on the photoluminescence spectra of Si nanocrystals embedded in SiO2

Fluorescent Si nanoparticle-based electrode for sensing biomedical substances

Investigation into Effects of Instability and Reactivity of Hydride-Passivated Silicon Nanoparticles on Interband Photoluminescence

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