Optimum composition of CaO, SrO dielectric materials in AC plasma display panels

The firing voltage Vfof ac operated plasma display panels can be reduced by coating the dielectric materials with (Ca, Sr)oxides. The reasons for the reduction of Vfare explained in this paper. The secondary electron emission yield, γi(Ar⁺), resulting from Ar ion bombardment, was directly measured for the compound oxides having various ratios of Ca to Sr. Also, the work function was obtained from the measurement of thermionic emission. The results show that γi(Ar⁺) reaches a maximum for a weight ratio of CaO to SrO of 1:3 while the work function reaches a minimum. From the results of Auger analysis and the measurement of optical absorption, it was confirmed that the most anion vacancies of SrO (F⁺s(H) color centers and F⁺scolor centers) were found in the sample of the preceding composition. (F⁺s(H) and F⁺scolor center are considered as a direct source of emission. As a result of the increase of (F⁺s(H) and F⁺scolor centers, reduction of the work function and increase of γi(Ar⁺) occur. The theoretical calculation of γi(Ar⁺), using the theory of Parilis et al., was carried out to clarify the influence of the work function upon γi(Ar⁺). The theoretical results are in good agreement with the measurement of γi(Ar⁺). From the discussion based on the potential ejection process in ae-plasma display panels, it is shown that the reduction mechanism of Vfis caused by the increase of F⁺scolor centers.