Effects of low energy protons on optical degradation of ZnO white paint

The formation and evolution of oxygen vacancies in ZnO white paint during exposure to less than 200 keV protons were investigated in terms of photoluminescence spectroscopy and X-ray photoelectron spectroscopy (XPS). The decreases of lattice oxygen and Zn vacancies which are respectively shown by XPS and photoluminescence spectroscopy, indicate that oxygen vacancies of ZnO white paint increases under the proton irradiation. The double ionized oxygen vacancies can trap electrons in the conductive bands to become the single ionized oxygen vacancies, leading to that the singly ionized oxygen vacancies gradually become the major defects induced by the proton irradiation. Proton irradiation leads to increase the amount of oxygen vacancy, and oxygen vacancy can trap electrons to form color cente