Radiation-induced formation of ZnO nanoparticles on the ZnSe single-crystal surface

The possible formation of ZnO nanocrystals was studied as a result of radiolysis of a ZnSe crystal surface exposed to zinc vapor and irradiated with gamma rays and in producing ZnSe-ZnO heterostructures. Under 60 Co gamma radiation in air, nanocrystals ∼27 nm in size are formed from nanoscopic ZnO nuclei. Under a mixed flux of gamma rays and thermal-neutron radiation, a twin structure is formed in the host ZnSe lattice and ZnO is removed. The oxide layer is also destroyed under proton irradiation in vacuum. It is found that the growth of ZnO nanocrystallites causes a manyfold increase in the luminescence intensity in the ∼600-nm band and in microhardness and also a decrease in the resistance and blocking and threshold voltages irrespective of polarity. Thus, gamma irradiation brings about the formation of light-emitting ZnSe-ZnO: Zn semiconductor structures with a p-n junction.