Efficient Acceptor Activation in AlxGa1−xN/GaN Doped Superlattices


Mg-doped superlattices consisting of uniformly doped AlxGa1−xN and GaN layers are analyzed by Hall-effect measurements. Acceptor activation energies of 70 meV and 58 meV are obtained for superlattice structures with an Al mole fraction ofx = 0.10 and 0.20 in the barrier layers, respectively. These energies are significantly lower than the activation energy measured for Mg-doped GaN thin films. At room temperature, the doped superlattices have free hole concentrations of 2 × 1018 cm−3 and 4 × 1018 cm−3 forx = 0.10 and 0.20, respectively. The increase in hole concentration with Al content of the superlattice is consistent with theory. The room temperature conductivity measured for the superlattice structures are 0.27 S/cm and 0.64 S/cm for an Al mole fraction ofx = 0.10 and 0.20, respectively.

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Goepfert, I.D., Schubert, E.F., Osinsky, A. et al. Efficient Acceptor Activation in AlxGa1−xN/GaN Doped Superlattices. MRS Online Proceedings Library 595, 385 (1999). https://doi.org/10.1557/PROC-595-F99W3.85

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