Regensburg 2002 – wissenschaftliches Programm
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HL: Halbleiterphysik
HL 3: Heterostrukturen I
HL 3.2: Vortrag
Montag, 11. März 2002, 10:45–11:00, H14
Spatial resolution of C-V profiles in very thin InAs layers embedded in GaAs — •Holger von Wenckstern1, Heidemarie Schmidt1, Rainer Pickenhain1, Fred Pietag2, Volker Gottschalch3, and Marius Grundmann1 — 1Universität Leipzig, Fakultät für Physik und Geowissenschaften — 2IOM Leipzig — 3Universität Leipzig, Fakultät für Chemie und Mineralogie
InAs monolayers embedded in GaAs have very efficient optical transitions between localized electron and hole states below the GaAs bandgap. This led, e.g., to the development of 1.5 ML InAs lasers acting at the wavelength of 870 nm [1]. The carrier distribution characteristics play an important role in the optical and electrical properties of such devices. Capacitance-voltage (C-V) measurements can be used to obtain information about the net doping profiles. We study the two-dimensional density of electrons in InAs quantum wells embedded in an Au/n-GaAs Schottky diode by means of C-V profiles measured at 300 K as a function of the InAs quantum well thickness (0.5-2.0 ML). Furthermore, we study the steplike characteristics of the C-V profile of 1 ML InAs as a function of the temperature. Calculating the temperature dependent Debye length and assuming that the steplike C-V profile of a quantum well is blurred for a Debye screening length smaller than the spatial extent of the ground-state wavefunction, we determine the spatial extent of the electron ground-state wavefunction of a 1 ML InAs/GaAs quantum well.
[1] A.R. Goni, M. Stroh, C. Thomsen, F. Heinrichsdorff, V. Türck, A.
Krost, D. Bimberg, Appl. Phys. Lett. 72, 1433 (1998).