Gas Desorption Analysis on the Surface of ZnO(0001̄) after Hydrogen Ion Irradiation

Abstract

The Gas desorption on the surface of zinc oxide (0001̄) after hydrogen ion irradiation was studied. The desorption gases were measured by means of temperature programmed desorption (TPD) from room temperature to 800°C. Most of the incident hydrogen ions were trapped in zinc oxide. The trapped hydrogen was desorbed in the form of H2 and H2O. The desorption of hydrogen was through a first-order reaction against hydrogen ion fluence, and the rate-determining process seemed to be hydrogen diffusion from the bulk to the surface. The desorption of water vapour which was caused by reaction between oxygen and hydrogen was limited by the desorption of hydrogen. When carbon monoxide was introduced 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 desorption spectrum with a peak at 530°C.