Microscopic electroabsorption line shape analysis for Ga(AsSb)/GaAs heterostructures
Bueckers, C, Blume, G, Thraenhardt, A, Schlichenmaier, C, Klar, PJ, Weiser, G, Koch, SW, Hader, J, Moloney, JV, Hosea, TJC, Sweeney, SJ, Wang, J-B, Johnson, SR and Zhang, Y-H (2007) Microscopic electroabsorption line shape analysis for Ga(AsSb)/GaAs heterostructures JOURNAL OF APPLIED PHYSICS, 101 (3), ARTN 0.
A series of Ga(AsSb)/GaAs/(AlGa) As samples with varying GaAs spacer width are studied by electric-field modulated absorption (EA) and reflectance spectroscopy and modeled using a microscopic theory. The analysis of the Franz-Keldysh oscillations of GaAs capping layer and of the quantum-confined Stark shift of the lowest quantum well (QW) transitions shows the strong inhomogeneity of the built-in electric field indicating that the field modulation due to an external bias voltage differs significantly for the various regions of the structures. The calculations demonstrate that the line shape of the EA spectra of these samples is extremely sensitive to the value of the small conduction band offset between GaAs and Ga(AsSb) as well as to the magnitude of the internal electric field changes caused by the external voltage modulation in the QW region. The EA spectra of the entire series of samples are modeled by the microscopic theory. The good agreement between experiment and theory allows us to extract the strength of the modulation of the built-in electric field in the QW region and to show that the band alignment between GaAs and Ga(AsSb) is of type II with a conduction band offset of approximately 40 meV.
|Divisions :||Faculty of Engineering and Physical Sciences > Electronic Engineering > Advanced Technology Institute > Photonics|
|Date :||1 February 2007|
|Identification Number :||10.1063/1.2433715|
|Uncontrolled Keywords :||Science & Technology, Physical Sciences, Physics, Applied, Physics, QUANTUM-WELL LASERS, 1.3 MU-M, OPTICAL-PROPERTIES, BLOCH EQUATIONS, GAIN SPECTRA, VCSEL, SEMICONDUCTORS, ABSORPTION, ALIGNMENT, FIELD|
|Related URLs :|
|Depositing User :||Mr Adam Field|
|Date Deposited :||27 May 2010 14:06|
|Last Modified :||23 Sep 2013 18:26|
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