Size-Dependent Intrinsic Radiative Decay Rates of Silicon Nanocrystals at Large Confinement Energies

Sýkora, Milan; Mangolini, Lorenzo; Schaller, Richard D.; Kortshagen, Uwe R.; Jurbergs, David; Klimov, Victor I.

doi:10.1103/physrevlett.100.067401

Cited by 156 publications

(166 citation statements)

References 23 publications

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“…While many experimental works point toward strong luminescence due to quantum-confined excitons in Si nanostructures fabricated with different methods [8,[11][12][13][14], others suggest that the PL emission arises from highly localized surface states [14][15][16][17]. Godefroo and co-authors, using PL measurements under high magnetic fields, showed that the optical emission of as-crystallized SiO x /SiO 2 superlattices may be related to defects, whereas it becomes entirely originated by excitonic quantum confinement (QC) after H passivation [7].…”

Section: Introductionmentioning

confidence: 99%

Optical emission fromSiO2-embedded silicon nanocrystals: A high-pressure Raman and photoluminescence study

et al. 2015

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We investigate the optical properties of high-quality Si nanocrystals (NCs)/SiO 2 multilayers under high hydrostatic pressure with Raman scattering and photoluminescence (PL) measurements. The aim of our study is to shed light on the origin of the optical emission of the Si NCs/SiO 2 . The Si NCs were produced by chemical-vapor deposition of Si-rich oxynitride (SRON)/SiO 2 multilayers with 5-and 4-nm SRON layer thicknesses on fused silica substrates and subsequent annealing at 1150°C, which resulted in the precipitation of Si NCs with an average size of 4.1 and 3.3 nm, respectively. From the pressure dependence of the Raman spectra we extract a phonon pressure coefficient of 8.5 ± 0.3 cm −1 /GPa in both samples, notably higher than that of bulk Si (5.1 cm −1 /GPa). This result is ascribed to a strong pressure amplification effect due to the larger compressibility of the SiO 2 matrix. In turn, the PL spectra exhibit two markedly different contributions: a higher-energy band that redshifts with pressure, and a lower-energy band which barely depends on pressure and which can be attributed to defect-related emission. The pressure coefficients of the higher-energy contribution are (−27 ± 6) and (−35 ± 8) meV/GPa for the Si NCs with a size of 4.1 and 3.3 nm, respectively. These values are sizably higher than those of bulk Si (−14 meV/GPa). When the pressure amplification effect observed by Raman scattering is incorporated into the analysis of the PL spectra, it can be concluded that the pressure behavior of the high-energy PL band is consistent with that of the indirect transition of Si and, therefore, with the quantum-confined model for the emission of the Si NCs.

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Section: Introductionmentioning

confidence: 99%

Optical emission fromSiO2-embedded silicon nanocrystals: A high-pressure Raman and photoluminescence study

et al. 2015

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“…The redshift of the PL spectrum of PSi by the light-illumination was reported, 28 but its mechanism is still unclear. We consider that the recombination at the surface-related states 31 may be attributed to this type of redshifted PL spectra. The present Ni/PSi composite powders with hydrophilic, superparamagnetic, and stable luminescence properties can be used for biomedical applications such as photodynamic therapy 3 and drug delivery 21 in microfluidic systems.…”

Section: Photoluminescence Properties Of Ni/psi Powdersmentioning

confidence: 99%

Properties of magnetic nickel/porous-silicon composite powders

Nakamura

Adachi

2012

AIP Advances

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The magnetic and photoluminescence (PL) properties of nickel/porous-silicon (Ni/PSi) composite powders are investigated. Ni/PSi composite powders are prepared by stain etching of Si powder in a HF/HNO3 solution followed by electroless plating of Ni nanoparticles on the stain-etched PSi powder in a NiCl2 solution. The Ni/PSi powders exhibit hydrophillicity, superparamagnetism caused by the deposited Ni nanoparticles, and orange-red PL owing to the nanostructured PSi surface. The degree of magnetization decreases with increasing Ni plating time, indicating its dependence on the size of the Ni nanoparticles. The Ni/PSi composite powders also show a stronger magnetization as compared to that of the Ni-particle-plated Si powder. The stronger magnetization results from the larger surface area of PSi. The PL intensity, peak wavelength, and lifetime of Ni/PSi are strongly dependent on the NiCl2 concentration. This dependence is due to the different thickness of the oxide overlayer on the PSi surface formed during the Ni plating process. The existence of the oxide overlayer also results in a small change in the PL intensity against excitation time

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“…This emission timescale is much faster than that of ls-scale emissions relating to defects reported in several studies of Sinanocrystals. 5,8 Therefore, the present fast PL components originate from intrinsic states of the individual Si-NDs. The relative intensity ratios of these two PL components as a function of excitation power are shown in Fig.…”

mentioning

confidence: 96%

“…Si nanostructures have extensively been studied owing to their potential applications in future photovoltaics and optoelectronics. [1][2][3][4][5][6][7][8][9][10][11] Si nanostructures with dimensions of less than 10 nm can behave as quantum dots (QDs) due to a three-dimensional quantum confinement effect for carriers. Minibands of carriers will arise from overlapping of the confined wavefunctions in high-density QDs regularly aligned.…”

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confidence: 99%

Picosecond transient photoluminescence in high-density Si-nanodisk arrays fabricated using bio-nano-templates

Kiba¹,

Mizushima²,

Igarashi³

et al. 2012

Appl. Phys. Lett.

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Over 100 ns intrinsic radiative recombination lifetime in type II InAs/GaAs1−xSbx quantum dots J. Appl. Phys. 111, 044325 (2012) Real-time synchrotoron radiation X-ray diffraction and abnormal temperature dependence of photoluminescence from erbium silicates on SiO2/Si substrates AIP Advances 2, 012141 (2012) Significantly improved minority carrier lifetime observed in a long-wavelength infrared III-V type-II superlattice comprised of InAs/InAsSb Appl. Phys. Lett. 99, 251110 (2011) Temperature and size dependence of time-resolved exciton recombination in ZnO quantum dots Appl. Phys. Lett. 99, 243107 (2011) Additional information on Appl. Phys. Lett.

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Size-Dependent Intrinsic Radiative Decay Rates of Silicon Nanocrystals at Large Confinement Energies

Cited by 156 publications

References 23 publications

Optical emission fromSiO2-embedded silicon nanocrystals: A high-pressure Raman and photoluminescence study

Optical emission fromSiO2-embedded silicon nanocrystals: A high-pressure Raman and photoluminescence study

Properties of magnetic nickel/porous-silicon composite powders

Picosecond transient photoluminescence in high-density Si-nanodisk arrays fabricated using bio-nano-templates

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