A Monte Carlo simulation of cathodoluminescence generated in ZnS phosphor powders

Abstract

Field emission displays (FEDs) are the possible full colour flat panel displays of the future. Studies on the FEDs include research on the applicability of wide band gap ZnS phosphors used in cathode ray tubes (CRT's) in the FED environment. Surface reactions occur on the ZnS surface during prolonged electron bombardment to form a non-luminescent ZnO layer with a consequent loss in cathodoluminescence (CL) intensity. Using a Monte Carlo algorithm, the electron energy loss within the ZnS layer of varying thickness on a ZnS substrate and determine the energy loss within the ZnS as function of the ZnO thickness. Since the oxide layer is non-luminescent, the energy loss within the ZnS in proportional to the generated CL. The results obtained correlate with experimental measurements of phosphor degradation during electron bombardment in UHV.