Residual native shallow donor in ZnO

High-energy electron irradiation in ZnO produces shallow donors at about E-C - 30 meV. Because the production rate is much higher for Zn-face (0001) than O-face (000 (1) over bar) irradiation, the donor is identified as a Zn-sublattice defect, most likely the interstitial Zn-I or a Zn-I-related complex. The donor energy is quite close to that of the unirradiated sample, and of other samples discussed in the literature, strongly suggesting that Zn-I (and not V-o) is the dominant native shallow donor in ZnO. An exceptionally high displacement threshold energy (similar to 1.6 MeV) is quantitatively explained in terms of a multiple-displacement model. [S0031-9007(99)08717-7].