Influence of defect states on the secondary electron emission yield γ from MgO surface

In order to study the dependence of the secondary electron emission yield γ on the defect states of the MgO surface in plasma display panels, cathodoluminescence (CL) spectra of MgO films, which were deposited at oxygen partial pressures of 0, 4.0×10−4, and 1.2×10−5 Torr, were measured. The CL intensities from the F (oxygen ion vacancy+one electron) and F+ (oxygen ion vacancy+one electron) centers of the MgO film that was deposited at high oxygen partial pressure (1.2×10−4 Torr), significantly increased with aging during discharge. Assuming that the probabilities of transitions are proportional to the measured CL intensities from the F and F+ bands of the MgO films, the γi values of MgO films for Ne and Xe ions, which include the F and F+ bands, were calculated. The tendencies of the breakdown voltages calculated using these γi values were consistent with those of the measured voltages of the MgO films. These calculated results suggested that the influence of the F and F+ bands on the γi values for Xe ions is large compared with that for Ne ions, and that the γi value of the MgO film for Xe ions increases with increasing numerical densities of the F and F+ centers, especially for F+ centers.