Conductive properties of sintered zinc oxide surface. The influence of electron irradiation and oxygen adsorption

The influence of irradiation with 5 MeV electrons on charge transport phenomena in the surface region of sintered ZnO was studied in the temperature range 200-600 K. Mobility and concentration of electrons were measured in the presence and absence of oxygen as a function of temperature both for irradiated and unirradiated samples. The influence of electron beam processing was found most pronounced for ZnO samples with absorbed oxygen. Radiation induced desorption of O2 was assumed to be responsible for enhanced effect of irradiation. Increased sensitivity of irradiated ZnO as an oxygen sensor has been observed and attributed to the formation of additional adsorption centres. A correlation between mobility of conduction electrons and their concentration in the surface region of irradiated ZnO with subsequently adsorbed oxygen was observed. (author)