We report on the electrical characterization of single-crystal ZnO and Au S
chottky contacts formed thereon before and after bombarding them with 1.8 M
eV protons. From capacitance-voltage measurements, we found that ZnO is rem
arkably resistant to high-energy proton bombardment and that each incident
proton removes about two orders of magnitude less carriers than in GaN. Dee
p level transient spectroscopy indicates a similar effect: the two electron
traps detected are introduced in extremely low rates. One possible interpr
etation of these results is that the primary radiation-induced defects in Z
nO may be unstable at room temperature and anneal out without leaving harmf
ul defects that are responsible for carrier compensation. (C) 2001 American
Institute of Physics.