GAS DESORPTION ANALYSIS ON THE SURFACE OF ZNO(000(1)BAR) AFTER HYDROGEN-ION IRRADIATION

The Gas desorption on the surface of zinc oxide (0001BAR) after hydrog en ion irradiation was studied. The desorption gases were measured by means of temperature programmed desorption (TPD) from room temperature to 800-degrees-C. Most of the incident hydrogen ions were trapped in zinc oxide. The trapped hydrogen was desorbed in the form of H-2 and H 2O. The desorption of hydrogen was through a first-order reaction agai nst hydrogen ion fluence, and the rate-determining process seemed to b e hydrogen diffusion from the bulk to the surface. The desorption of w ater vapour which was caused by reaction between oxygen and hydrogen w as limited by the desorption of hydrogen. When carbon monoxide was int roduced on the zinc oxide surface under hydrogen ion irradiation, the hydrogen desorption spectrum was different from that of only hydrogen irradiation. The difference between these spectra was similar to the d esorption spectrum with a peak at 530-degrees-C.