Dresden 2006 – wissenschaftliches Programm

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HL: Halbleiterphysik

HL 9: Poster I

HL 9.22: Poster

Montag, 27. März 2006, 15:15–17:45, P3

Thermopower measurements on n-type (Ga,In)(N,As) — •J. Teubert, P. J. Klar, W. Heimbrodt, K. Volz, W. Stolz, and P. Thomas — Dept. Physics and WZMW, Philipps-University of Marburg, Germany

We present first thermopower measurements on n-type-(Ga,In)(N,As) semiconductor alloys. N in (Ga,In)(N,As) forms a highly localized energy level resonant with the conduction band that strongly perturbs the conduction band structure of the crystal. The interaction between the localized N-related levels and the extended conduction band states leads to a strong dependence of the local band gap on nitrogen concentration. Together with the variation of the local N-environment this results in significant spatial and energetic disorder. For example, these effects manifest themselves in the magnetotransport behaviour of n-type (Ga,In)(N,As), which is dominated by weak Anderson localization effects. Combined thermopower and resistivity measurements can be analysed using models established for amorphous semiconductors. This analysis yields further insight into the nature (i.e. lengthscale, width) of the disorder potential fluctuations.