Electronic structure of shallow impurities in GaN studied via bound exciton magnetooptics

We report the photoluminescence experiments on high quality GaN samples in high magnetic fields. A detailed analysis of the recombination due to excitons bound to neutral donors and acceptors is presented. Special attention is focussed on transitions for which the impurity is left in the excited state (so called two electron satellites). These results show a rich energetic structure of excited states of the impurity involved in such a recombination process. The magnetic field dependence of the energy structure of the shallow neutral donor and acceptor in GaN is then discussed. The validity of the effective mass approximation for shallow impurities in wide gap semiconductors is examined. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)