Defect states of transition metal-doped MgO for secondary electron emission of plasma display panel

High secondary electron emission (SEE) yield is one of the important properties of MgO for industrial applications such as alternating-current plasma display panel (AC-PDP), which reduces the firing voltage for discharge. SEE induced by low-energy Ne and Xe ions can be described by potential emission mechanism of Auger neutralization. Defect states in MgO can play an important role in enhancing the SEE. The electronic density of states of Ti-, Cr-, Fe-, Ni-, Zn-doped and undoped MgO was calculated using CASTEP. The occupied defect levels of the Ti-, Cr-, Fe-, Ni- and Zn-doped MgO are at 5.23, 3.90, 2.76, 1.22 and 0.06 eV above the valence band, respectively. Higher defect level appears to be advantageous for getting larger SEE yield. Considering the fact that Ti-doped MgO reveals n-type conductivity, Cr seems to be the proper dopant among the studied elements for the purpose of high SEE yield in AC-PDP.