<i>In situ</i>photoluminescence/Raman study of reversible photo-induced structural transformation of nc-Si

Yukhymchuk, Volodymyr; Dzhagan, Volodymyr; Valakh, M. Ya.; Kladko, V. P.; Gudymenko, O J; Yefanov, V.S.; Zahn, Dietrich R. T.

doi:10.1088/2053-1591/1/4/045905

Cited by 7 publications

(6 citation statements)

References 44 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A similar photo-induced phase transition effect was already observed on other types of Si nanostructures, as reported earlier in the literature [ 35 , 37 , 38 ]. The photo-induced formation of the hex-Si phase is known to be stimulated by strong mechanical stresses, appearing in a homogeneously heated nanostructured Si-based sample.…”

Section: Resultssupporting

confidence: 87%

“…On the contrary, the Raman spectra at a much higher excitation level (2.15 mW), shown in Figure 5 b, are significantly different. They can be easily deconvoluted into several Lorentzian-like peaks: (i) heated cubic phase (at 512 cm −1 ); (ii) hexagonal phase (495 cm −1 ); and (iii) amorphous phase (very large band centered at 475 cm −1 ) [ 37 ]. The hexagonal phase dominates in the porous Si samples with empty pores, while the Raman spectrum of the porous Si/hexadecane composites is mainly defined by the cubic phase spectral band.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Liquid-Modulated Photothermal Phenomena in Porous Silicon Nanostructures Studied by μ-Raman Spectroscopy

2023

View full text Add to dashboard Cite

In the present study, the effect of liquid filling of the nanopore network on thermal transport in porous Si layers was investigated by μ-Raman spectroscopy. The values of thermal conductivity of porous Si and porous Si-hexadecane composites were estimated by fitting the experimentally measured photoinduced temperature rise with finite element method simulations. As a result, filling the pores with hexadecane led to (i) an increase in the thermal conductivity of the porous Si-hexadecane composite in a wide range of porosity levels (40–80%) and (ii) a suppression of the characteristic laser-induced phase transition of Si from cubic to hexagonal form.

show abstract

Section: Resultssupporting

confidence: 87%

Section: Resultsmentioning

confidence: 99%

Liquid-Modulated Photothermal Phenomena in Porous Silicon Nanostructures Studied by μ-Raman Spectroscopy

2023

View full text Add to dashboard Cite

show abstract

“…Laser-induced heating has a significant effect on phase transformation in Si nanostructures [ 22 , 61 ]. At room temperature, the cubic phase (c-Si) exhibits diamond-like cubic structure where each Si atom is distant from its four nearest neighbors at 2.73 Å.…”

Section: Resultsmentioning

confidence: 99%

Photothermal Effects and Heat Conduction in Nanogranular Silicon Films

et al. 2021

View full text Add to dashboard Cite

We present results on the photothermal (PT) and heat conductive properties of nanogranular silicon (Si) films synthesized by evaporation of colloidal droplets (drop-casting) of 100 ± 50 nm-sized crystalline Si nanoparticles (NP) deposited on glass substrates. Simulations of the absorbed light intensity and photo-induced temperature distribution across the Si NP films were carried out by using the Finite difference time domain (FDTD) and finite element mesh (FEM) modeling and the obtained data were compared with the local temperatures measured by micro-Raman spectroscopy and then was used for determining the heat conductivities k in the films of various thicknesses. The cubic-to-hexagonal phase transition in Si NP films caused by laser-induced heating was found to be heavily influenced by the film thickness and heat-conductive properties of glass substrate, on which the films were deposited. The k values in drop-casted Si nanogranular films were found to be in the range of lowest k of other types of nanostructurely voided Si films due to enhanced phonon scattering across inherently voided topology, weak NP-NP and NP-substrate interface bonding within nanogranular Si films.

show abstract

“…For CdSe and CdS TO modes are usually not observed, due to the domination of the Fröhlich electron-LO-phonon coupling in these polar compounds. For elemental semiconductor NCs like Si and Ge, a single optical phonon mode exists and manifests itself in Raman spectra [99,129,177], and is sometimes referred to as 'TO' [178,179].…”

Section: Quasi-free-standing Ncsmentioning

confidence: 99%

Vibrational spectroscopy of compound semiconductor nanocrystals

Dzhagan

Azhniuk

Milekhin

2018

J. Phys. D: Appl. Phys.

Self Cite

107

View full text Add to dashboard Cite

A review of recent applications of Raman spectroscopy as a fast, sensitive, and non-destructive technique for exploring II–VI semiconductor nanocrystals fabricated by various methods (colloidal chemistry, Langmuir–Blodgett method, diffusion-limited growth) is presented. Specific size-related features revealed in the nanocrystal Raman spectra (phonon confinement, surface phonons) are analysed, as well as more complicated size effects for ultrasmall nanocrystals (NCs) related to the activation of the phonon density of states modified by surface reconstruction. Similarities and differences of the Raman scattering in II–VI and III–V or elemental (Si) semiconductor NCs are briefly analysed. Implementation of resonant conditions and application of infrared absorption analysis, complementary to the Raman spectroscopy—resulting in the observation of phonon modes ‘silent’ in conventional Raman scattering processes—are discussed. Furthermore, Raman spectroscopy is employed for fast and efficient assessment of the composition of matrix-embedded ternary II–VI nanocrystals, as well as more complicated multimode quaternary II–VI systems. Selective probing of electronic and vibrational spectra of different parts of heterogeneous NCs (such as core–shell systems) by tuning the excitation wavelength in resonant Raman scattering is considered. The analysis of phonon spectra is applied to the quantitative estimation of strain in the core and shell, and degree of interface intermixing, as well as to checking the surface oxidation. The above approaches and phenomena are further explored in more complex compound NCs beyond II–VI, such as CuInS2/ZnS. Recent results in the field of surface- and tip-enhanced Raman spectroscopy and surface-enhanced infrared absorption are analysed showing the perspectives of Raman spectroscopy as a tool for investigation of single-nanocrystal phonon spectra.

show abstract

In situphotoluminescence/Raman study of reversible photo-induced structural transformation of nc-Si

Cited by 7 publications

References 44 publications

Liquid-Modulated Photothermal Phenomena in Porous Silicon Nanostructures Studied by μ-Raman Spectroscopy

Liquid-Modulated Photothermal Phenomena in Porous Silicon Nanostructures Studied by μ-Raman Spectroscopy

Photothermal Effects and Heat Conduction in Nanogranular Silicon Films

Vibrational spectroscopy of compound semiconductor nanocrystals

Contact Info

Product

Resources

About