The Electronic Structure and Luminescence of Phosphors Based on IIA-VIB Compounds
For the understanding of the mechanism of luminescence excitation in the phosphors of IIA-VIB compounds the luminescence excitation and fundamental absorption spectra have been investigated. The measurements were performed using electron synchrotrons as radiation sources in the 5–45 eV region. The reflection spectra of evaporated thin films of alkaline earth sulphides CaS, SrS, BaS and single crystals of MgO, CaO, SrO are reported. The optical properties have been derived by Kramers-Kronig analysis of reflection data in the fundamental absorption region. Fine structure was interpreted as exciton and interband transitions from the valence band and from the cation core level of p-symmetry. For the investigation of energy migration the spectra of luminescence were studied. In the excitation spectra a sudden increase of the luminescence yield at photon energy more than 2 Eg was observed. The measurements at high energy show an increase of the luminescence yield which may be due to photon multiplication.
KeywordsReflection Spectrum Excitation Spectrum Absorption Edge Energy Migration Photon Multiplication
Unable to display preview. Download preview PDF.
- 1.V. L. Levshin, Proc. Intern. Conf. on Lum., 1966, AABudapest, p. 39.Google Scholar
- 2.V. L. Levshin, V. V. Mikhailin, Proc. Intern. Conf. on Lum., 1966, AABudapest, p. 1508.Google Scholar
- 3.B. K. Novosadov, L. K. Saulewitch (Kulman), D. T. Swiridow, Ju. F. Smirnov, Dokl. Akad. Nauk SSSR, 184, 82 (1969)Google Scholar
- 4.L. Kulman, V. Mikhailin, Tr. I FA Tartu (in press).Google Scholar
- 7.V. L. Levshin, V. V. Mikhailin, L. K. Saulevitch, Izv. Akad. Nauk SSSR, 33, 947 (1969).Google Scholar
- 8.E. R. Ilmas, Ch. B. Lushchik, Tr. IFA, 34, 5, 1966.Google Scholar