抄録
Absorption, emission and excitation spectra of KCl:Pb and KBr:Pb have been measured at various temperatures. These observed spectra are similar to those of KCl:Tl, and the absorption bands seemed to be due to transitions in Pb++ ions which occupies the normal positive ion sites. The two principal excited states are 1P1 and 3P1 of Pb++ ion. 273 mμ absorption, 345 mμ emission in KCl:Pb and 302 mμ absorption, 365 mμ emission in KBr:Pb are attributed to 3P1–1S0 transitions perturbed by surrounding host lattice ions. The excitation to 1P1 state does not manifest any dstinct emission which is different from the case of Tl activated phosphors. The near ultra-violet emission suffers violent thermal quenching at room temperature, and the activation energies of these non-radiative process are found to be 0.28 eV and 0.18 eV for KCl:Pb and KBr:Pb, respectively.
Several discussions using a single configuration coordinate model are given.
