Optical characteristics of tungsten trioxide luminescence in different matrices

Abstract

The comparative research using time-resolved spectroscopy of the optical characteristics of an emission in two types phosphors: natural phosphors: ZnWO4, CdWO4, microcrystalline WO3, and artificial once: wide band gap dielectrics LiF, MgF2и BaF2 doped with tungsten trioxide were presented. Both single crystals and сeramic samples obtained in the process of high-speed radiation synthesis in air under a flux of 1.5 MeV elec- trons were studied. It has been established that the spectral-kinetic characteristics of the studied materials lu- minescence are the similarity in dielectrics, where WO3 is present as a dopant; in semiconductors (MeWO4), where tungsten trioxide is present as WO62‒ oxyanion and in crystal lattice of tungsten trioxide binary com- ponent. It is found that tungsten trioxide, being doped in dielectric, forms a subband of impurity states in the dielectric band gap, due to which, of spatial separation of electron-hole impurity pairs becomes possible upon optical excitation of the dielectric.