An identification of shallow bound exciton centers was presented, based upon magneto-optical measurements and diffusion experiments. The thermalization behavior of the Zeeman split components confirmed that the I4, I6, I8 and I9 exciton lines arose from donor-bound exciton complexes. The results were supported by theoretical analysis of shallow bound exciton complexes which revealed the Γ7 symmetry of the upper valence band. The presence of 2-electron satellites related to the respective transitions was further evidence for donor-bound complexes and permitted the determination of donor binding energies. Thus, H, Al, Ga and In were identified, as producing the I4, I6, I8 and I9 lines, by doping, diffusion and annealing experiments combined with photoluminescence and secondary ion mass spectrometry.

Identification of Bound Exciton Complexes in ZnO. Strassburg, M., Rodina, A., Dworzak, M., Haboeck, U., Krestnikov, I.L., Hoffmann, A., Gelhausen, O., Phillips, M.R., Alves, H.R., Zeuner, A., Hofmann, D.M., Meyer, B.K.: Physica Status Solidi B, 2004, 241[3], 607-11