The relation between low resistivity and Zn interstitial in ZnO single crystals implanted with the peak Si atomic concentration of 2.62 x 1020 cm−3 was studied by combining Rutherford back-scattering spectroscopy and channelling, photoluminescence, and Van der Pauw methods. The variation in resistivity from about 104Ωcm for un-implanted ZnO to about 10−3Ωcm for as-implanted ones was observed. The lattice displacement of Zn atoms of about 0.10Å from the <0001> row was estimated from the normalized angular yield profiles, preserving the single crystallinity in as-implanted ZnO with a minimum yield (χmin) of about 11%. The low resistance was maintained by the annealing (1000C), accompanied with the lattice displacement of Zn atoms of about 0.07Å. These results suggested the existence of the shallow donor consisting of Zn interstitial and/or Zn interstitial-related complex corresponding to a newly appeared 3.33eV emission located at about 40meV from the bottom of the conduction band.

Evaluation of Zinc Interstitial in Si-Ion Implanted ZnO Bulk Single Crystals by a Rutherford Backscattering Study: an Origin of Low Resistivity. Y.Izawa, K.Matsumoto, K.Kuriyama, K.Kushida: Nuclear Instruments and Methods in Physics Research B, 2010, 268[11-12], 2104-6