Determination of the charge carrier concentration and mobility in n‐gap by Raman spectroscopy

Irmer, G.; Toporov, V. V.; Bairamov, B. H.; Monecke, J.

doi:10.1002/pssb.2221190219

Cited by 162 publications

(85 citation statements)

References 8 publications

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“…Nevertheless, the plasmon-phonon coupling of GaP is much less explored than GaAs. Previous Raman studies [37][38][39][40] reported that, as in GaAs, the LOPC frequency upshifted from ν LO upon n-type doping, though the lower branch was never observed. Upon p-type doping, the LOPC frequency of GaP upshifted slightly from ν LO 39,40 , contrary to the downshift that is established for p-type GaAs.…”

Section: Introductionmentioning

confidence: 88%

Dynamically coupled plasmon-phonon modes in GaP: An indirect-gap polar semiconductor

et al. 2015

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The ultrafast coupling dynamics of coherent optical phonons and the photoexcited electron-hole plasma in the indirect gap semiconductor GaP are investigated by experiment and theory. For below-gap excitation and probing by 800-nm light, only the bare longitudinal optical (LO) phonons are observed. For above-gap excitation with 400-nm light, the photoexcitation creates a high density, nonequilibrium e−h plasma, which introduces an additional, faster decaying oscillation due to an LO phonon-plasmon coupled (LOPC) mode. The LOPC mode frequency exhibits very similar behavior for both n-and p-doped GaP, downshifting from the LO to the transverse optical (TO) phonon frequency limits with increasing photoexcited carrier density. We assign the LOPC mode to the LO phonons coupled with the photoexcited multi-component plasma. For the 400-nm excitation, the majority of the photoexcited electrons are scattered from Γ valley into the satellite X valley, while the light and spin-split holes are scattered into the heavy hole band, within 30 fs. The resulting mixed plasma is strongly damped, leading to the LOPC frequency appearing in the reststrahlen gap. Due to the large effective masses of the X electrons and heavy holes, the coupled mode appears most distinctly at carrier densities 5 × 10 18 cm −3 . We perform theoretical calculations of the nuclear motions and the electronic polarizations following an excitation with an ultrashort optical pulse to obtain the transient reflectivity responses of the coupled modes. We find that, while the longitudinal diffusion of photoexcited carriers is insignificant, the lateral inhomogeneity of the photoexcited carriers due to the laser intensity profile should be taken into account to reproduce the major features of the observed coupled mode dynamics.

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Section: Introductionmentioning

confidence: 88%

Dynamically coupled plasmon-phonon modes in GaP: An indirect-gap polar semiconductor

et al. 2015

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“…Many of the LOPCM analyses of Raman spectra in polar semiconductors have been carried out using either a Drude model 12,34,35 or the hydrodynamical model 4,10,36,37 for the free-carrier electric susceptibility. The computational simplicity of these two models as compared with the more involved Lindhard-Mermin calculations has favored their widespread use in the analysis of Raman spectra.…”

Section: Comparison Between the Drude And The Hydrodynamical Modelmentioning

confidence: 99%

“…The values of the reduced Fermi energy (E F /k B T) found for samples A -H range from Ϫ1. 35 for the lowest doping sample ͑A͒, to 8.27 for the highest doping sample ͑H͒. Consequently, the use of the Fermi-Dirac distribution function is necessary for a realistic description of the electron plasma through the whole range of carrier concentrations.…”

mentioning

confidence: 99%

Raman scattering by LO phonon-plasmon coupled modes inn-type InP

et al. 1999

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We have studied LO phonon-plasmon coupled modes by means of Raman scattering in n-InP for carrier densities between 6ϫ10 16 and 1ϫ10 19 cm Ϫ3 . A line-shape theory based on the Lindhard-Mermin dielectric function that takes into account the nonparabolicity of the InP conduction band as well as temperature and finite wave-vector effects is used to fit the Raman spectra and extract accurate values of the electron density. The results obtained from the Lindhard-Mermin model are compared with the charge density determinations based on the Drude and the hydrodynamical models, and the approximations involved in these models are discussed. ͓S0163-1829͑99͒10431-4͔

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“…In n-type samples, the predominant mechanism causing the Raman shift of the LO mode is the coupling interaction between LO phonons and overdamped plasmons [35,36].…”

Section: Raman Spectroscopymentioning

confidence: 99%

Donor-acceptor-pair emission characterization in N-B doped fluorescent SiC

Ou¹,

Jokubavičius²,

Kamiyama³

et al. 2011

Opt. Mater. Express

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Abstract:In the present work, we investigated donor-acceptor-pair emission in N-B doped fluorescent 6H-SiC, by means of photoluminescence, Raman spectroscopy, and angle-resolved photoluminescence. The photoluminescence results were interpreted by using a band diagram with Fermi-Dirac statistics. It is shown that with N and B concentrations in a range of 10 18 cm −3 the samples exhibit the most intense luminescence when the concentration difference (n-type) is about 4.6x10 18 cm −3 . Raman spectroscopy studies further verified the doping type and concentrations for the samples. Furthermore, strong luminescence intensity in a large emission angle range was achieved from angle-resolved photoluminescence. The results indicate N-B doped fluorescent SiC as a good wavelength converter in white LEDs applications. References and links1. H. Yamamoto, "White LED phosphors: the next step," Proc. SPIE 7598, 759808 (2010). 2. P. Schlotter, R. Bompiedi, and J. Schneider, "Luminescence conversion of blue light emitting diodes," Appl.Phys. A 64, 417-418 (1997 183-194 (2008). 33.

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Determination of the charge carrier concentration and mobility in n‐gap by Raman spectroscopy

Cited by 162 publications

References 8 publications

Dynamically coupled plasmon-phonon modes in GaP: An indirect-gap polar semiconductor

Dynamically coupled plasmon-phonon modes in GaP: An indirect-gap polar semiconductor

Raman scattering by LO phonon-plasmon coupled modes inn-type InP

Donor-acceptor-pair emission characterization in N-B doped fluorescent SiC

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