Takuji Tsujita

Energy Distribution of Ion-Induced Secondary Electrons from MgO Surface

Energy distributions of ion-induced secondary electrons (IISEs) from a MgO thin-film surface were investigated. An abnormal IISE emission was observed in addition to the normal one and it continued after ion irradiation was cut off, and thus was a so-called self-sustained electron emission. The energies of the abnormal secondary electrons (SEs) are lower than the vacuum level at the MgO surface. In addition, the energy distribution of the abnormal SEs is very close to the profile of the density of states of the valence band (VB). The results strongly suggest that the abnormal SEs are emitted from the VB of MgO by the field emission.

44.3: Investigation of Effects of Heating in Air on Ionization Potential of MgO and CaO Films using Metastable De‐excitation Spectroscopy

Effects of heating in air on the ionization potentials, Eip, of MgO and CaO films were investigated using metastable de-excitation spectroscopy (MDS). The difference in Eip between samples with and without heating in air was found to be small for MgO and significant for CaO. In addition, the difference in the ion-induced secondary electron yield, γ, which is expected from Eip determined from the MDS spectra, between samples with and without heating in air qualitatively agrees with that expected from the measurement of the firing voltage using a test panel. The present results conformed that MDS is effective to evaluating γ of the protective layer used in plasma display panels.