Femtosecond response times and high optical nonlinearity in beryllium-doped low-temperature grown GaAs

Haiml, M.; Siegner, U.; Morier‐Genoud, F.; Keller, U.; Luysberg, M.; Specht, P.; Weber, E. R.

doi:10.1063/1.123521

Cited by 71 publications

(40 citation statements)

References 14 publications

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“…13 These dopants should not contribute to parasitic parallel conduction since they are deactivated through compensation by high-density dislocations and defects (vacancies and antisites). 14,15 In this work, we propose the use of low growth temperature, specifically 510 C, and beryllium dopants to enhance the crystal quality of GaSb-based materials grown on GaAs. The temperature chosen is high enough to obtain 2 Â 8 surface reconstruction indicative of the single monolayer of Sb before the GaSb growth, 16 which has been observed to favour IMF formation.…”

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confidence: 99%

Solid solution strengthening in GaSb/GaAs: A mode to reduce the TD density through Be-doping

Gutiérrez

Araújo

Jurczak

et al. 2017

Applied Physics Letters

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The need for a low bandgap semiconductor on a GaAs substrate for thermophotovoltaic applications has motivated research on GaSb alloys, in particular, the control of plastic relaxation of its active layer. Although interfacial misfit arrays offer a possibility of growing strain-free GaSb-based devices on GaAs substrates, a high density of threading dislocations is normally observed. Here, we present the effects of the combined influence of Be dopants and low growth temperature on the threading dislocation density observed by Transmission Electron Microscopy. The Be-related hardening mechanism, occurring at island coalescence, is shown to prevent dislocations to glide and hence reduce the threading dislocation density in these structures. The threading density in the doped GaSb layers reaches the values of seven times less than those observed in undoped samples, which confirms the proposed Be-related hardening mechanism.

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mentioning

confidence: 99%

Solid solution strengthening in GaSb/GaAs: A mode to reduce the TD density through Be-doping

Gutiérrez

Araújo

Jurczak

et al. 2017

Applied Physics Letters

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“…In the present experiment, the high density Mn doping brings acceptor levels with density as high as 10 19 cm −3 . Thus the trapping and non-radiative recombination of photo-excited carriers should be very efficient and the carrier lifetime is less than 1ps 20,21 . The resolution-limited fast decay of ∆R/R within 1ps corresponds to such a rapid non-radiative recombination process.…”

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confidence: 99%

Observation of the spin-charge thermal isolation of ferromagneticGa0.94Mn0.06Asby time-resolved magneto-optica

et al. 2003

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The dynamics of magnetization under femtosecond optical excitation is studied in a ferromagnetic semiconductor Ga 0.94 Mn 0.06 As with a time-resolved magneto-optical Kerr effect measurement with two color probe beams. The transient reflectivity change indicates the rapid rise of the carrier temperature and relaxation to a quasi-thermal equilibrium within a few ps, while a very slow rise of the spin temperature of the order of 500ps is observed. This anomalous behavior originates from the thermal isolation between the charge and spin systems due to the spin polarization of carriers (holes) contributing to ferromagnetism. This constitutes experimental proof of the halfmetallic nature of ferromagnetic Ga 0.94 Mn 0.06 As arising from the large exchange energy of carriers compared to Fermi energy.

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“…Another proof of the point defect model was obtained by investigating the LTG GaAs layers doped with Be impurities [69,74]. This model assumes that the non-equilibrium electrons in the LTG GaAs are trapped at the ionised As Ga donors.…”

Section: Electron Trapping Timesmentioning

confidence: 99%

Semiconductors for terahertz photonics applications

Krotkus¹

2010

J. Phys. D: Appl. Phys.

112

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Abstract:Generation and measurement of ultrashort, sub-picosecond pulses of electromagnetic radiation with their characteristic Fourier spectra that reach far into terahertz (THz) frequency range has recently become a versatile tool of the far-infrared spectroscopy and imaging. This technique -THz time-domain spectroscopy, in addition to a femtosecond pulse laser, requires semiconductor components manufactured from materials with a short photoexcited carrier lifetime, high carrier mobility, and large dark resistivity. Here we will review most important developments in the field of investigation of such materials. Main characteristics of low-temperature-grown or ion-implanted GaAs and semiconducting compounds sensitive in the wavelength ranges around 1 µm and 1.5 µm will be surveyed. The second part of the paper is devoted to the effect of surface emission of THz transients from semiconductors illuminated by femtosecond laser pulses. Main physical mechanisms leading to this emission as well as their manifestation in various crystals will be described.

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Femtosecond response times and high optical nonlinearity in beryllium-doped low-temperature grown GaAs

Cited by 71 publications

References 14 publications

Solid solution strengthening in GaSb/GaAs: A mode to reduce the TD density through Be-doping

Solid solution strengthening in GaSb/GaAs: A mode to reduce the TD density through Be-doping

Observation of the spin-charge thermal isolation of ferromagneticGa0.94Mn0.06Asby time-resolved magneto-optica

Semiconductors for terahertz photonics applications

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