Phosphor having resistance to deterioration caused by ultraviolet rays and gas discharge display device of which image quality is not readily deteriorated over time

摘要

A manganese-activated zinc silicate phosphor according to the present invention satisfies 0< beta - alpha≤0.5 and 1.7≤beta , where a value alpha is a ratio of a number of zinc atoms to a number of silicon atoms in a surface region of a phosphor particle, including a surface of the phosphor particle and a vicinity thereof, and a value beta is a ratio of a number of zinc atoms to a number of silicon atoms in a whole of the phosphor particle.