Exciton motion under an external electric field in GaAs

Aoki, Kazunori; Okuyama, Y.; Kobayashi, Toshihiko; Yamamoto, Keiichi

doi:10.1088/0022-3719/12/4/011

Cited by 7 publications

(3 citation statements)

References 9 publications

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“…We find that the UPB line shifts to the higher energy side with increasing applied electric fields, while the LPB line shifts to the lower energy side. Such shifts have been reported by Aoki et al [5,6] and Weisbuch [lo]. Aoki et al ascribed the shifts to the exciton-electron inelastic collisions.…”

Section: Discussionsupporting

confidence: 73%

“…HOWever, it should be pointed out that the lineshapes in the exciton region are very complicated and identification of the emission lines is difficult as discussed later. From the best fitting procedure Aoki et al [5] obtained the broadening factor of 43 meV, which is unreasonably large. I n order to avoid the complexity we estimated the exciton or polariton temperature by analyzing the LO phonon replica.…”

Section: Resultsmentioning

confidence: 99%

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Effect of Electric Fields on Luminescence in GaAs

Yamawaki

Hamaguchi

1982

Physica Status Solidi (b)

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Photoluminescence spectra near the exciton region are investigated under the application of external electric fields parallel and perpendicular t o epitaxial GaAs surfaces. Quenching of the luminescence is observed and explained in terms of impact ionization of excitons. The emission peaks of the upper (UPB) and lower polariton branches (LPB) shift t o higher and lower energy sides, respectively, with increasing the electric fields or the excitation intensity. The calculated peak of the L P B emission is located around 1.515 eV and shifts to higher energy side and dominates the U P B emission, which is contradictory to the present observation. Kew emission peak appears a t 1.515 eV under a n application of an electric field in pure samples with carrier concentrations less than 6 x 1013 C I I~-~.Photolumineszenzspektren in der NIhe des Exziton-Bereichs werden unter Anwendung von externen elektrischen Feldern parallel und senkrecht zur epitaktischen GaAs-Obcrflichc untersncht. Tilgung der Lumineszenz wird beobachtet und mit StoDionisntion von Exzitonen erklart.Die Emissionsmasima der oberen (UPB) und tieferen Polaritonzweige (LDP) verschieben sich zur hochenergetischen bzw. niederenergetischen Seite mit wnchsenden elektrischen Feldern oder der ilnregnngsenergie. Das berechnete Maximum der LPB-Emission ist bei etwa 1,515 eV lokalisiert nnd verschiebt sich ziir hiiherenergetischen Seite und dominiert iiber die UPB-Emission, was im Gegensatz zu den dnrgelegten Beobachtnngen ist. Ein ncues Emissionsmaximum tritt bei 1,515 eV nnter Ankgen eines elektrischen Feldes in reinen Proben mit Tragerkonzentrationen von wenigcr als 6 x 1013 auf.

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Section: Discussionsupporting

confidence: 73%

Section: Resultsmentioning

confidence: 99%

Effect of Electric Fields on Luminescence in GaAs

Yamawaki

Hamaguchi

1982

Physica Status Solidi (b)

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“…This is because the sample length is short (approximately 2.4 μm), and different bias voltage can pick out different initial states and lead to different hopping conduction paths. Mesoscopic fluctuation effects have been observed in 1D- 46 and 2D-semiconductor field-effect transistors (FET) structures 47 that have the same order of dimension in which the differential conductance oscillates when varying the number of the electrons in the FET channel through the gate voltage. The oscillations have been explained on the basis of a model of a "main" hop.…”

Section: Methodsmentioning

confidence: 99%

Electron localization in metal-decorated graphene

Wang

et al. 2011

Phys. Rev. B

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By decorating single-layer graphene with disordered noble metal (Ag, Au, and Pt) clusters, we investigated experimentally the influence of strong random scatterings on graphene transport and electron-localization phenomena. As evidenced by micro-Raman scattering, there is a strong interction between the metal clusters and graphene. We found that such a strong interaction was the consequence of plasma-assisted decoration of the graphene by the metal clusters. A large negative magnetoresistance (MR) effect (up to 80% at 12 T) was observed and fitted using different models. The structure, size, and area density of metal clusters were characterized by scanning tunneling microscopy and transmission electron microscopy. The samples with a high concentration of scattering centers behaved as insulators at low temperatures and showed strong localization (SL) effects. Their temperature-dependent conductance was in accordance with the two-dimensional variable-range hopping (VRH) mechanism. The localization lengths and density of states were estimated and discussed.

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Exciton Impact Ionization and Electric Conductivity in Germanium at Low Temperature

Nöldeke

Metzger

Huebener

et al. 1985

Physica Status Solidi (b)

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The exciton luminescence intensity and the electric conductivity are measured simultaneously during optical excitation in high-purity Ge and in p-doped Ge a t 4.2 l< as o function of an applied electric field. With increasing field the exciton density decreases due to exciton impact ionization. The carriers which are set free by this process result in a distinct increase in the electric conductivity. For undoped Ge ths results agree well with a rate equation model based on impact ionization of the excitons. In the p-doped Ge impurity impact ionization is found to have a strong influence in addition to impact ionization of the excitons.Die Exzitonenlumineszenzintensitat und die elektrische Leitfahigkeit von hochreinem Ge und p-leitendem Ge werden simultan wahrend optischer Anregung bei 4,2 K in Abhangigkeit vom elektrischen Feld gemessen. Nit wachsendem Feld nimmt die Exzitonendichte infolge von Exzitonen-stoBionisation ab. Die durch diesen ProzeB freigesetzten Ladungstrager fiihren zu einer deutlichen Erhohung der elektrischen Zeitfahigkeit,. Fur undotiertes Germanium stimmen die Ergebnisse gut mit einem Bilanzgleichungsmodell uberein, das auf StoBionisation der Exzitonen beruht. Fur p-leitendes Ge wird gefunden, daB Storstellenionisation zusiitzlich zur StoBionisation der Exzitonen einen starken EinfluB hat.

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Exciton motion under an external electric field in GaAs

Cited by 7 publications

References 9 publications

Effect of Electric Fields on Luminescence in GaAs

Effect of Electric Fields on Luminescence in GaAs

Electron localization in metal-decorated graphene

Exciton Impact Ionization and Electric Conductivity in Germanium at Low Temperature

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