Phonon dispersion and Raman spectra of wurtzite InAs under pressure

Dabhi, Shweta D.; Jha, Prafulla K.

doi:10.1016/j.jpcs.2015.03.014

Cited by 15 publications

(5 citation statements)

References 39 publications

(72 reference statements)

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“…The Raman peaks between 215 and 232 cm −1 are the transversal optical (TO) mode at ≈226 cm −1 , the longitudinal optical (LO) mode at ≈232 cm −1 and the

E_2^H

mode of WZ InAs at ≈215 cm −1 . [ 37,38 ] The InAs reference NW spectrum also shows three peaks below 140 cm −1 which can be attributed to the second‐order acoustic modes. Moreover, we also observe a peak at ≈272 cm −1 , which is due to the mixture of transversal optical and transversal acoustic (TO+TA) modes.…”

Section: Resultsmentioning

confidence: 99%

InAs–InP Superlattice Nanowires with Tunable Phonon Frequencies

Zannier,

Trautvetter,

Sivan

et al. 2024

Advanced Physics Research

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The control of heat conduction through the manipulation of phonons in solids is of fundamental interest and can be exploited in applications for thermoelectric conversion. In this context, the advent of novel semiconductor nanomaterials with high surface‐to‐volume ratio, e.g. nanowires, offer exciting perspectives, leading to significant leaps forwarding the efficiency of solid‐state thermoelectric converters after decades of stagnation. Beyond the high aspect ratio, the nanowire geometry offers unprecedented possibilities of materials combination and crystal phase engineering not achievable with 2D counterparts. In this work, the growth of long (up to 100 repetitions) wurtzite InAs/InP superlattice nanowires with homogeneous segment thicknesses is reported, with control down to the single digit of nanometer. By means of Raman scattering experiments, clear modifications of the phonon dispersion in superlattice nanowires are found, where both InAs‐like and InP‐like modes are present. The experimentally measured modes are well reproduced by density functional perturbation theory calculations. Remarkably, it is found that the phonon frequencies can be tuned by the superlattice periodicity, opening exciting perspectives for phonon engineering and thermoelectric applications.

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“…The Raman peaks between 215 and 232 cm −1 are the transversal optical (TO) mode at ≈226 cm −1 , the longitudinal optical (LO) mode at ≈232 cm −1 and the

E_2^H

Section: Resultsmentioning

confidence: 99%

InAs–InP Superlattice Nanowires with Tunable Phonon Frequencies

Zannier,

Trautvetter,

Sivan

et al. 2024

Advanced Physics Research

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show abstract

“…Moreover, the formation energy decreases from −0.36 eV (GaAs) to −0.23 eV (InAs) which shows GaAs is more thermodynamically stable than InAs (See Table 1 ). Furthermore, the positive phonon frequencies of GaAs and InAs are reported in the literature, which ensures their dynamic stability [ 28 , 29 ]. Therefore, the doping in between these two end binaries must be stable.…”

Section: Resultsmentioning

confidence: 99%

Evaluation of In Doped GaAs Alloys to Optimize Electronic, Thermoelectric and Mechanical Properties

Alhodaib

2022

Materials

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The electronic, mechanical and transport properties of the In substitution in GaAs are investigated by the TB-mBJ potential, BoltzTraP code and Charpin tensor matrix analysis using Wien2k code. The formation energies of the alloys Ga1−xInxAs (x = 0.0, 0.25, 0.50, 0.75 and 1.0) confirm that they are thermodynamically favorable. The directional symmetry changes when increasing the In concentration and reduces the bandgap from 1.55 eV (GaAs) to 0.57 eV (InAs), as well as reducing the electrical conductivity and increasing the Seebeck coefficient. The thermoelectric performance is depicted by the power factor without including lattice vibration. The elastic properties’ analysis shows mechanical stability, and elastic moduli decrease with an increasing In in GaAs, which converts the brittle nature to ductile. The Debye temperature, hardness and thermal conductivity decrease, thus, increasing their importance for device fabrications.

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“…

normalΔ ω ((),, T) = normalΔ ω_{TE} ((),, T) + normalΔ ω_{S} ((),, T) + normalΔ ω_{A} ((),, T)

where ∆ω TE (T), ∆ω S (T) and ∆ω A (T) denote the wavenumber shift due to thermal expansion, interfacial strain and anharmonicity in lattice, respectively. In the present case, the range of temperature effect is taken to be below Debye temperature (250 K) to avoid significant contribution due to anharmonicitiy. Therefore, we can neglect the anharmonic part.…”

Section: Resultsmentioning

confidence: 99%

Spatially resolved Raman spectroscopy study of uniform and tapered InAs micro‐nano wires: correlation of strain and polytypism

Gupta

Ingale

Pal

et al. 2017

J Raman Spectroscopy

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The asymmetric peak ~212–218 cm−1 occurring in InAs micro‐nanowires (MNWs: diameter: 2 μm – 400 nm) is investigated using spatially resolved Raman spectroscopy of uniform, bent and long tapered MNWs grown on a Si (001) substrate. It is attributed to superposition of E2h phonon (wurtzite: WZ) and TO phonon (zinc blende: ZB) of InAs. Polarized and wavelength‐dependent spatially resolved Raman spectroscopy establishes the presence of WZ and ZB phases in these MNWs. However, formation of WZ phase for larger diameter InAs MNWs is not commensurate with existing growth mapping studies. Further, study of these MNWs suggests that the fraction of WZ to ZB content in a MNW depends not only on the diameter but also seems to be governed by local growth seeding/conditions. This in turn leads to either tapered or uniform MNW growth under the same (external) growth conditions. The variation of these wavenumbers that of bulk value is correlated to the residual stress present in ZB and WZ phases due to the presence of the other (WZ/ZB) phase. Consistently, temperature‐dependent Raman data show that there is a measurable contribution of stress to dω/dT, a positive for ZB and negative for WZ phonons, due to differences in their thermal expansions. Further, effective thermal expansion coefficient of WZ InAs in the presence of ZB phase is calculated to vary in the range 10–19 × 10−6/K from base to tip of a MNW at ~80 K, which is not possible to determine otherwise. Copyright © 2017 John Wiley & Sons, Ltd.

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Phonon dispersion and Raman spectra of wurtzite InAs under pressure

Cited by 15 publications

References 39 publications

InAs–InP Superlattice Nanowires with Tunable Phonon Frequencies

InAs–InP Superlattice Nanowires with Tunable Phonon Frequencies

Evaluation of In Doped GaAs Alloys to Optimize Electronic, Thermoelectric and Mechanical Properties

Spatially resolved Raman spectroscopy study of uniform and tapered InAs micro‐nano wires: correlation of strain and polytypism

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