New explanation of Raman peak redshift in nanoparticles

Meilakhs, A. P.; Koniakhin, Sergei V.

doi:10.1016/j.spmi.2017.08.010

Cited by 30 publications

(30 citation statements)

References 20 publications

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“…Independent determination of NC size is not possible. The relationship between Raman peak shift and NC size is obtained taking into account the discretness of NCs lattice vibrations [23]. In NCs much smaller than the phonon mean free path, phonons experience several reflection and scattering on NCs surfaces during phonon life time.…”

Section: Resultsmentioning

confidence: 99%

“…To differentiate the shift induced by phonon confinement and stress we have used a model developed by Ref. [23] for phonon confinement induced shifts. Size of NCs have been obtained using HRTEM cross section micrographs to be used in the calculation NC size from the PCM.…”

Section: Discussionmentioning

confidence: 99%

“…In this work, we apply the improved PCM developed in Ref. [23] for Ge NCs embedded in Si x N y matrix to determine size and correlating with transmission electron microscopy data. Among many NCs, Ge NCs seems to have many advantages over other alternative semiconductors, because of its compatibility with silicon technology and also due to its stronger QCE compared with Si which leads to easier tunability of its band gap.…”

Section: Introductionmentioning

confidence: 99%

“…This method provides a nondestructive method to determine size and size distribution of nanocrystals. Separating the opposing shifts of compressive stress and phonon confinement, here we report on a test of an improved model for phonon confinement [23] for Ge NCs embedded in silicon nitride matrix.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Correlation of TEM data with confined phonons to determine strain and size of Ge nanocrystals embedded in SixNy matrix

Bahariqushchi

Gündoğdu

Aydınlı

2017

Superlattices and Microstructures

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a b s t r a c tModels that use phonon confinement fail to provide consistent results for nanocrystal sizes in differing dielectric matrices due to varying stress experienced by nanocrystals in different dielectric environments. In cases where direct measurement of stress is difficult, the possibility of stress saturation as a function of size opens up a window for the use of phonon confinement to determine size. We report on a test of this possibility in Ge: Si x N y system. Ge nanocrystals (NCs) embedded in silicon nitride matrix have been fabricated using plasma enhanced chemical vapor deposition (PECVD) followed by post annealing in Ar ambient. Nanocrystal size dependence of Raman spectra was studied taking into account associated stress and an improved phonon confinement approach. Our analysis show same stress for NCs which have sizes below 7.0 nm allowing the use of phonon confinement to determine the nanocrystal size. The results are compared with TEM data and good agreement is observed.

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Section: Resultsmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Correlation of TEM data with confined phonons to determine strain and size of Ge nanocrystals embedded in SixNy matrix

Bahariqushchi

Gündoğdu

Aydınlı

2017

Superlattices and Microstructures

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“…The studies are concerning the relation between the size of nanocrystals and the peak shift [4][5][6] and the width of the peak [4,5,7].…”

Section: Introductionmentioning

confidence: 99%

Influence of geometry of nanocrystals on the Raman spectra

Igo¹

2018

Nanosystems: Phys. Chem. Math.

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It is shown that Raman spectra of nanocrystals with complex geometric shape can acquire additional broadening. In order to describe complex geometric shapes of nanocrystals in terms of its influence on the Raman spectrum, a parameter was introduced for the shape -roughness parameter. The roughness is defined as a relative parameter of the presence of additional volume on the faces of the cubic nanocrystal. The calculations for additional broadening of the Raman spectral line were made for 3-10 nm nanodiamonds.

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Predicting Raman line shapes from amorphous silicon clusters for estimating short‐range order

Rani

Tanwar

Kandpal

et al. 2021

J Raman Spectroscopy

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A theoretical model obtained based on direct matrix method and bond polarization model (DMM-BPM) has been used to predict Raman scattering line shape for amorphous silicon (a-Si). These line shapes can describe the observed nonunique peak position from these a-Si crystallites, unlike crystalline Si, that varies between 470 and 485 cm −1 . The model has been validated using three different sets of Raman scattering data by fitting it with the proposed model. The Raman spectra are obtained from a-Si samples prepared by three different methods by three different research groups reported earlier.Clear consonance with the experimentally observed and theoretical Raman line shape was obtained. The model has also been used to estimate the distance up to which the crystallinity remains intact in a-Si. The used model has been compared with the existing phonon confinement model, and a discrepancy (in the latter) therein has been discussed. Rationale behind adopting this model has been explained using the constraints related to the Raman selection rule, their relaxation, or breakdown in appropriate materials' regimes. A handy empirical relation between Raman peak position and amorphous cluster size has been proposed.

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New explanation of Raman peak redshift in nanoparticles

Cited by 30 publications

References 20 publications

Correlation of TEM data with confined phonons to determine strain and size of Ge nanocrystals embedded in SixNy matrix

Correlation of TEM data with confined phonons to determine strain and size of Ge nanocrystals embedded in SixNy matrix

Influence of geometry of nanocrystals on the Raman spectra

Predicting Raman line shapes from amorphous silicon clusters for estimating short‐range order

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