Monochromic orange emission of Pr3+ ions in phosphate glass

Abstract

Zinc strontium phosphate glasses doped with different trivalent praseodymium ion (Pr 3þ ) concentrations are presented and their photoluminescence properties are investigated upon 442 nm excitation. With the Pr 3þ concentration decreasing, the orange emission of Pr 3þ ( 1 D 2 − 3 H J ) is enhanced steadily at the cost of its blue emission ( 3 P 1;0 − 3 H 4 ). Monochromic orange emission of Pr 3þ ions is obtained when the Pr 3þ doping is reduced to 0.05 mol.%. The mechanism controlling the monochromatic characteristic of Pr 3þ emissions is supposed to be associated with the phonon-aided nonradiative relaxation process of Pr 3þ : 3 P j → 1 D 2 , which depends on the Pr 3þ concentration as well as the phonon energy of the glass matrix. Sodium zinc tellurite and barium gadolinium germinate glasses with the lower phonon energy are used as reference hosts to clarify this mechanism, and the results obtained support this suggestion.