Impurity absorption of SrS-Ce3+ phosphors

We investigate the impurity absorption of SrS−Ce phosphors. For this purpose, we measure the spectra of diffuse reflection of powder phosphors. It is established that the introduction of Ce simultaneously with a coactivator gives rise to a strong absorption band at 2.88 eV, and the introduction of a coactivator (NH₄F, NH₄Cl, NH₄Br, NH₄I, LiCl, NaCl or KCl), to an absorption band at about 2.36 eV. We assume that the absorption band at 2.88 eV is caused by that portion of Ce introduced that forms the center of luminescence of Ce³⁺. Tartu University, Estonian, Republic, 18, Yulikooli St., Tartu, EE2400, Estonia. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 4, pp. 542–544, July–August, 1997.