The characterisation of porous silicon by Raman spectroscopy

Goodes, Stephen R.; Jenkins, Tim; Beale, M.I.J.; Benjamin, J. D.; Pickering, C.

doi:10.1088/0268-1242/3/5/011

Cited by 62 publications

(13 citation statements)

References 22 publications

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“…31,32 These features can be supported by our Raman analyses, where we have determined nanocrystallite size of our PS samples. Different confinement models have been used to calculate particle size.…”

Section: 142829supporting

confidence: 62%

Influence of applied current density on the nanostructural and light emitting properties of n-type porous silicon

Çetinel

Artunç

Şahin

et al. 2015

Int. J. Mod. Phys. B

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Effects of current density on nanostructure and light emitting properties of porous silicon (PS) samples were investigated by field emission scanning electron microscope (FE-SEM), gravimetric method, Raman and photoluminescence (PL) spectroscopy. FE-SEM images have shown that below 60 mA/cm 2 , macropore and mesopore arrays, exhibiting rough morphology, are formed together, whose pore diameter, pore depth and porosity are about 265-760 nm, 58-63 µm and 44-61%, respectively. However, PS samples prepared above 60 mA/cm 2 display smooth and straight macropore arrays, with pore diameter ranging from 900-1250 nm, porosity of 61-80% and pore depth between 63-69 µm. Raman analyses have shown that when the current density is increased from 10 mA/cm 2 to 100 mA/cm 2 , Raman peaks of PS samples shift to lower wavenumbers by comparison to crystalline silicon (c-Si). The highest Raman peak shift is found to be 3.2 cm −1 for PS sample, prepared at 90 mA/cm 2 , which has the smallest nanocrystallite size, about 5.2 nm. This sample also shows a pronounced PL, with the highest blue shifting, of about 12 nm. Nanocrystalline silicon, with the smallest nanocrystallite size, confirmed by our Raman analyses using microcrystal model (MCM), should be responsible for both the highest Raman peak shift and PL blue shift due to quantum confinement effect (QCE).

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Section: 142829supporting

confidence: 62%

Influence of applied current density on the nanostructural and light emitting properties of n-type porous silicon

Çetinel

Artunç

Şahin

et al. 2015

Int. J. Mod. Phys. B

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“…Raman scattering was employed to gain more insight into the microstructure of the arrays. Numerous studies document Raman scattering from bulk Si, 38 amorphous Si, 39 and various nanostructured intermediates such as nanocrystals, [40][41][42] porous Si, 43 and nanowires. 44,45 For bulk Si in the backscattering geometry, the primary feature of the Raman signal is a sharp peak occurring near 520 cm À1 generated by the zonecenter LO phonon, with intrinsic full-width at half-maximum (FWHM) 38 $2.6 cm À1 corresponding to an energy relaxation timescale of $2.1 ps.…”

Section: Probing Microstructure Using Raman Spectroscopymentioning

confidence: 99%

Thermal conductivity of silicon nanowire arrays with controlled roughness

Feser

Sadhu

Azeredo

et al. 2012

Journal of Applied Physics

125

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A two-step metal assisted chemical etching technique is used to systematically vary the sidewall roughness of Si nanowires in vertically aligned arrays. The thermal conductivities of nanowire arrays are studied using time domain thermoreflectance and compared to their high-resolution transmission electron microscopy determined roughness. The thermal conductivity of nanowires with small roughness is close to a theoretical prediction based on an upper limit of the mean-free-paths of phonons given by the nanowire diameter. The thermal conductivity of nanowires with large roughness is found to be significantly below this prediction. Raman spectroscopy reveals that nanowires with large roughness also display significant broadening of the one-phonon peak; the broadening correlates well with the reduction in thermal conductivity. The origin of this broadening is not yet understood, as it is inconsistent with phonon confinement models, but could derive from microstructural changes that affect both the optical phonons observed in Raman scattering and the acoustic phonons that are important for heat conduction. V

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“…Goodes et al 21 used Raman scattering to characterize the P-Si produced in the early years and interpreted the observed features associated with an amorphous component within P-Si. After the first observations of strong RT photoluminescence (PL) and electroluminescence (EL) from P-Si, Tsu et al 22 established a correlation between Raman and PL spectra and showed that the observed PL originates from extremely small microstructures.…”

Section: Raman Scattering From Porous Si Membranesmentioning

confidence: 99%

Multi-Technique Study of Porous Silicon Membranes by Raman Scattering, Ftir, Xps, Aes and Sims

Feng¹,

Wee²

1994

Porous Silicon

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Optical and surface analytical techniques of Raman scattering, Fourier transform infrared (FTIR) spectroscopy, x-ray photoelectron spectroscopy, Auger electron spectroscopy and secondary ion mass spectrometry have been used to study porous Si membranes with visible light emission. The Raman features from porous Si membranes are markedly distinct from that of crystalline, microcrystalline and amorphous Si. Their anomalous Raman-temperature behavior is explained by the quantum wire model and strain effects. Their FTIR spectra show a large number of infrared active modes due to the oxidized and organized surfaces of the pores. Surface analyses reveal the main components of surface layers to be Si02 plus Si clusters and some contamination elements. The depth distributions of these impurities over the entire 200 [xm thick membrane are determined. The combination of surface and optical analyses offers a better understanding of the properties of porous Si.

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The characterisation of porous silicon by Raman spectroscopy

Cited by 62 publications

References 22 publications

Influence of applied current density on the nanostructural and light emitting properties of n-type porous silicon

Influence of applied current density on the nanostructural and light emitting properties of n-type porous silicon

Thermal conductivity of silicon nanowire arrays with controlled roughness

Multi-Technique Study of Porous Silicon Membranes by Raman Scattering, Ftir, Xps, Aes and Sims

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