A study of the secondary electron yield γ of insulator cathodes for plasma display panels

In order to provide a guideline in the search for the optimum cathode materials for plasma display panels (PDPs), formulas for the simple calculation of the secondary electron yield gamma were derived from Hagstrum's theory for an insulator without impurity levels, From these, we obtained the generalized relations between gamma and the band parameters of an insulator and the potential energy of an incident particle, which is an ion or a metastable atom, Unlike metals, it is not work function but the sum of band gap and electron affinity that essentially contributes to gamma of an insulator. By applying these formulas, the gamma values of BaO and MgO for He, Ne, Ar, Kr, and Xe ions and metastable atoms were practically calculated. In particular, the metastable atom-induced gamma values of these insulators were calculated for the first time. The gamma values of these insulators for these noble gas ions are determined by Auger neutralization only, As for MgO, which is at present the most useful insulator cathode for PDPs, the gamma values for Kr and Xe ions become zero. These calculated gamma values of MgO for all noble gas ions were compared with experimental results reported previously.