Picosecond Dynamics of Optical Gain Duo to Electron-Hole Plasma in GaAs under Near Band-Gap Excitation

Tanaka, Shosaku; Kuwata, Takaaki; Hokimoto, Takehiro; Kobayashi, Hiroshi; Saitô, Hiroshi

doi:10.1143/jpsj.52.677

Cited by 13 publications

(3 citation statements)

References 17 publications

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“…Figure 3c shows an example of the spectra for Δ t = 9.6 ns. We observe that the amplitude of the conductivity does not decrease with increasing pump fluence which would be the characteristics of a dominant electron-hole recombination mechanism 24 25 . (See Supplementary Fig.…”

Section: Resultsmentioning

confidence: 77%

Long-range and high-speed electronic spin-transport at a GaAs/AlGaAs semiconductor interface

Nádvorník

Němec

Janda

et al. 2016

Sci Rep

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Spin-valves or spin-transistors in magnetic memories and logic elements are examples of structures whose functionality depends crucially on the length and time-scales at which spin-information is transferred through the device. In our work we employ spatially resolved optical pump-and-probe technique to investigate these fundamental spin-transport parameters in a model semiconductor system. We demonstrate that in an undoped GaAs/AlGaAs layer, spins are detected at distances reaching more than ten microns at times as short as nanoseconds. We have achieved this unprecedented combination of long-range and high-speed electronic spin-transport by simultaneously suppressing mechanisms that limit the spin life-time and the mobility of carriers. By exploring a series of structures we demonstrate that the GaAs/AlGaAs interface can provide superior spin-transport characteristics whether deposited directly on the substrate or embedded in complex semiconductor heterostructures. We confirm our conclusions by complementing the optical experiments with dc and terahertz photo-conductivity measurements.

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Section: Resultsmentioning

confidence: 77%

Long-range and high-speed electronic spin-transport at a GaAs/AlGaAs semiconductor interface

Nádvorník

Němec

Janda

et al. 2016

Sci Rep

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“…Even when the carrier density is reduced by two orders ofmagnitude, conditions are kept so as to trace the luminescence decay in the regime of decreasing carrier density in each crystallite rather than that of diminishing number of radiating crystallites. However, at high excitation the EHP can be brought out of thermal carrier recombination routes generally depends on the effective temperature (for example, the band-to-band radiative recombination is enhanced with decreasing EHP temperature [24]; the surface recombination rate is heating influences the luminescence kinetics [25,26] and has to be taken into consideration. reflects the relaxation of the carrier density and effective…”

Section: Introductionmentioning

confidence: 99%

Carrier recombination in CdS nanocrystals under single-electron and high-density excitation

Juršėnas

Stepankevieius

Strumskis

et al. 1995

Semicond. Sci. Technol.

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Room-temperature green luminescence has been studied in laser-modified (darkened) CdS nanocrystals with the average radii B ranging above the exciton Bohr radius (from 3.3 nm to 100 nm). Under high picosecond-pulse excitation, the electron-hole plasma decay kinetics exhibited adecrease of lifetime with decreasing crystallite size, enabling the surface recombination with the velocity of 1.3 x lo3 cm s-' to be revealed. Under low cw excitation, a striking increase in the luminescence intensity of nanocrystals with one excited electron-hole pair was discovered for average radii below 10 nm. The bulk-like bimolecular recombination with the constant of 3 x 10"0cm3s-' was shown to account for the observed size dependence.

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“…3c shows an example of the spectra for ∆t = 9.6 ns. We observe that the amplitude of the conductivity does not decrease with increasing pump fluence which would be the characteristics of a dominant electron-hole recombination mechanism [23,24]. (See Supplementary information Sec.…”

Section: Dc-transport and Thz-spectroscopy Measurements Of The Electr...mentioning

confidence: 95%

Nanosecond spin-transfer over tens of microns in a bare GaAs/AlGaAs layer

Nádvorník,

Němec,

Janda

et al. 2015

Preprint

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The spin-conserving length-scale is a key parameter determining functionalities of a broad range of spintronic devices including magnetic multilayer spin-valves in the commercialized magnetic memories or lateral spin-transistors in experimental spin-logic elements. Spatially resolved optical pump-and-probe experiments in the lateral devices allow for the direct measurement of the lengthscale and the time-scale at which spin-information is transferred from the injector to the detector. Using this technique, we demonstrate that in an undoped GaAs/AlGaAs layer spins are detected at distances reaching more than ten microns from the injection point at times as short as nanoseconds after the pump-pulse. The observed unique combination of the long-range and highrate electronic spin-transport requires simultaneous suppression of mechanisms limiting the spin life-time and mobility of carriers. Unlike earlier attempts focusing on elaborate doping, gating, or heterostructures we demonstrate that the bare GaAs/AlGaAs layer intrinsically provides superior spin-transport characteristics whether deposited directly on the substrate or embedded in complex heterostructures.

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Picosecond Dynamics of Optical Gain Duo to Electron-Hole Plasma in GaAs under Near Band-Gap Excitation

Cited by 13 publications

References 17 publications

Long-range and high-speed electronic spin-transport at a GaAs/AlGaAs semiconductor interface

Long-range and high-speed electronic spin-transport at a GaAs/AlGaAs semiconductor interface

Carrier recombination in CdS nanocrystals under single-electron and high-density excitation

Nanosecond spin-transfer over tens of microns in a bare GaAs/AlGaAs layer

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