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18. Optical properties of low-temperature grown GaAs on Bragg reflectors.

Author

Giehler, M., Herfort, J., Ulrici, W., Da¨weritz, L., and Ploog, K. H.

Subjects
GALLIUM arsenide, LOW temperatures, SPECTRAL reflectance
Abstract

Near-infrared reflectance spectra of 5 µm thick low-temperature (LT) GaAs films grown by molecular-beam epitaxy at different substrate temperatures T[sub G] on GaAs/A1As Bragg reflectors (BR's) have been studied. With decreasing T[sub G] (increasing absorption coefficient α[sub f] of the film), the reflectance of the stop band of the BR decreases monotonously, while the amplitudes of the interference fringes due to the LT-GaAs layer inside the stop band initially increase followed by a decrease for large α[sub f] values. This unusual behavior is explained by a particular optical interference effect of a thick absorbing layer on a strongly reflecting structure. This effect remarkably improves the determination of α[sub f] and enables the detection of As-antisite defects in LT-GaAs films for concentrations as low as 1 × 10[sup 18] cm[sup -3], where other methods fail. [ABSTRACT FROM AUTHOR]

Published
2002
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32. Time-resolved measurements on 2T2 -> 2E photoluminescence of Ti3+ in GaP

Author

Roura Grabulosa, Pere, Benyattou, T., Guillot, G., Moncorge, R., Ulrici, W., and Universitat de Barcelona

Subjects
Semiconductors, Luminescència, Photoluminescence
Abstract

The time dependence of the 2 T 2 → 2 E photoluminescence transition of Ti 3 + Ga in GaP has been measured on semi-insulating, p-type conducting, and n-type conducting samples. A decay time τ 0 =2.0 μs was obtained at T=10 K. The temperature dependence of the decay time in the conducting samples is found to be affected by the capture of free carriers by Ti 3 + Ga in the excited state whereas the results on p-type conducting samples suggest hole localization at the Ti 3 + Ga .

Published
1992

33. Photoluminescence excitation spectroscopy of Ti 3+ in GaP

Author

Roura, P., Guillot, G., Benyattou, T., Ulrici, W, Laboratoire de physique de la matière (LPM), Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA), and GUILLOT, Gérard

Subjects
[SPI]Engineering Sciences [physics], [SPI] Engineering Sciences [physics], ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
1991

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