Using high pressure to unravel the mechanism of visible emission in amorphous Si/SiO<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mrow /><mml:mi>x</mml:mi></mml:msub></mml:math>nanoparticles

Goñi, A. R.; Muniz, Leonardo; Reparaz, J. S.; Alonso, M. I.; Garriga, M.; Lopeandía, A. F.; Rodríguez‐Viejo, J.; Arbiol, Jordi; Rurali, Riccardo

doi:10.1103/physrevb.89.045428

Cited by 14 publications

(5 citation statements)

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“…In spite of much effort to investigate the optical properties of nanosized Si, the actual origin of its strong PL signal is still under debate [7][8][9][10]. 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].…”

Section: Introductionmentioning

confidence: 99%

“…These authors obtained pressure coefficients in close agreement with those of bulk Si (−14.1 meV/GPa) [19], concluding that the bright emission in their samples mainly arises from the indirect transition in Si. Recently, Goñi et al [10] have used high-pressure experiments to investigate the origin of the visible emission in amorphous Si/SiO x nanoparticles. Although these authors report PL pressure coefficients that are sizably lower than those of bulk Si, they still conclude that the strong PL signal in their samples is determined by QC, which is supported by the fact that their experimental pressure coefficients seem to be systematically related to nanoparticle sizes and emission energies.…”

Section: Introductionmentioning

confidence: 99%

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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%

Section: Introductionmentioning

confidence: 99%

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

et al. 2015

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“…65 Actually, the study of the photoluminescence of these structures at high hydrostatic pressures from both the theoretical and the experimental point of view is a sign of their quantum confinement. 65 Other two-dimensional nanostructures studied in the framework of their thermoelectric performance were Cr/V 2 O 5 thin films (with ZT of 0.16 at room temperature 66 ), Al:ZnO sputtered thin films (with a ZT over 0.1, three times bigger than previously reported values 67 ), silicon thin layers and graphene membranes, both from the theoretical 28,40,68 and experimental 43 point of view.…”

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Review—Towards the Next Generation of Thermoelectric Materials: Tailoring Electronic and Phononic Properties of Nanomaterials

Caballero-Calero

D’Agosta

2017

ECS J. Solid State Sci. Technol.

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In this review article we present the most relevant outcomes of the joint project “Tailoring Electronic and Phononic Properties of Nanomaterials: Towards Improved Thermoelectricity (nanoTHERM)”, a Spanish research Consolider project focused on the understanding of the thermoelectric materials and the tailoring of both their electronic and phononic properties toward the optimization of the efficiency of thermoelectric devices working at low and high temperatures.

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“…Here we can only speculate, arguing as in the case of the pressure dependence of optical transitions in amorphous Si nanoparticles embedded in a substoichiometric oxide matrix [62]. In this paper, it was shown by combining high-pressure PL experiments and ab-initio band structure calculations that the sign and magnitude of the pressure derivative of transition energies from different electron states are solely determined by the confinement energy.…”

Section: B Effect Of the Hydrostatic Pressurementioning

confidence: 99%

Electronic wave functions and optical transitions in (In,Ga)As/GaP quantum dots

et al. 2016

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Document VersionPublisher's PDF, also known as Version of Record (includes final page, issue and volume numbers) Please check the document version of this publication:• A submitted manuscript is the author's version of the article upon submission and before peer-review. There can be important differences between the submitted version and the official published version of record. People interested in the research are advised to contact the author for the final version of the publication, or visit the DOI to the publisher's website.• The final author version and the galley proof are versions of the publication after peer review.• The final published version features the final layout of the paper including the volume, issue and page numbers. Link to publicationCitation for published version (APA): Robert, C., Pereira Da Silva, K., Nestoklon, M. O., Alonso, M. I., Turban, P., Jancu, J-M., ... Cornet, C. (2016). Electronic wave functions and optical transitions in (In,Ga)As/GaP quantum dots. Physical Review B, 94(7), 1-11. [075445]. DOI: 10.1103/PhysRevB.94.075445 General rightsCopyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights.• Users may download and print one copy of any publication from the public portal for the purpose of private study or research.• You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal ? Take down policyIf you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim. We study the complex electronic band structure of low In content InGaAs/GaP quantum dots. A supercell extended-basis tight-binding model is used to simulate the electronic and the optical properties of a pure GaAs/GaP quantum dot modeled at the atomic level. Transitions between hole states confined into the dots and several X Z -like electronic states confined by the strain field in the GaP barrier are found to play the main role on the optical properties. Especially, the calculated radiative lifetime for such indirect transitions is in good agreement with the photoluminescence decay time measured in time-resolved photoluminescence in the µs range. Photoluminescence experiments under hydrostatic pressure are also presented. The redshift of the photoluminescence spectrum with pressure is also in good agreement with the nature of the electronic confined states simulated with the tight-binding model.

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Using high pressure to unravel the mechanism of visible emission in amorphous Si/SiOxnanoparticles

Cited by 14 publications

References 84 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

Review—Towards the Next Generation of Thermoelectric Materials: Tailoring Electronic and Phononic Properties of Nanomaterials

Electronic wave functions and optical transitions in (In,Ga)As/GaP quantum dots

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