Optical properties of KCl:Sn 2+ phosphors synthesized from aqueous KCl/SnCl 2 solutions

Abstract

KCl:Sn 2+ phosphors were synthesized from aqueous KCl/SnCl 2 solutions. Solvents with a molar ratio of KCl: SnCl 2 1: M (M 0 - 5) were dissolved in de-ionized water. The optical properties of the synthesized phosphors were investigated by photoluminescence (PL) analysis, PL excitation spectroscopy (PLE), and PL lifetime measurements. KCl:Sn 2+ phosphor synthesized with M 0.1 exhibited the strongest PL emission in the green (A T band) and red spectral regions (R band). The phosphors synthesized with M 1 were composites of various potassium chlorostannates and emitted light in the red spectral region (R band). Annealing the M 0.1 phosphor in dry N 2 resulted in a PL spectrum that was the same as those usually observed in melt-grown KCl:Sn 2+ phosphors (i.e., exhibiting only the A T emission band). Annealing also led to a change in the PL decay characteristic from a double exponential curve to a single exponential curve. The A T and R emission bands had nearly the same PLE spectra and were related to the deexcitation of the Sn 2+ (5s5p) ions in KCl. © 2011 American Institute of Physics.