Regensburg 2004 – wissenschaftliches Programm

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HL: Halbleiterphysik

HL 44: Poster II

HL 44.47: Poster

Donnerstag, 11. März 2004, 16:30–19:00, Poster A

Magnetotransport in doped GaAsN and GaInNAs layers — •J. Teubert, P.J. Klar, W. Heimbrodt, K. Volz, and W. Stolz — FB Physik und WZMW, Philipps-Universität, Marburg

Incorporation of small amounts of nitrogen into GaAs and GaInAs results in large changes of the electronic properties of these materials. Whereas the optical properties are already extensively studied, there is only little knowledge about the effects of nitrogen incorporation onto the electronic transport behaviour of these III-V alloys. Magnetoresistance (MR) and Hall measurements at temperatures between 2 and 280 K and fields up to 10 T show large negative MR effects and anomalous Hall effects for n-type samples whereas p-type samples behave like conventional III-V alloys. This can be explained qualitatively with the energetic and spatial disorder induced by N in the conduction band. We present first magnetotransport measurements under hydrostatic pressure up to 20 kbar for n-type GaNAs samples with low N concentrations. In these samples applying hydrostatic pressure allows one to tune the energetic positions of the localized N-cluster states with respect to the conduction band edge. The effects on the transport properties are discussed.