30.3: Reduction of Electron‐Beam‐Induced Degradation of ZnS Green Phosphor Coated with Phosphate

Electron-beam-induced luminescence degradation is found to be reduced in ZnS: Cu, Al phosphor coated with a limited low content of phosphate. The behavior of the degradation is correlated with the quantities of SO2 and H2O gases released from the phosphors, analyzed by temperature programmed desorption-mass spectrometry (TPD-MS) and transmission electron microscopy (TEM) observations. We find that the layer coated with the appropriate phosphate content is uniform and continuous, which prevents the surface chemical reactions that cause the degradation.