Saturation processes of photoluminescent pigments embedded in sinterized glass

Abstract

Light emission from long-life phosphorescent pigments is produced in the form of curves whose shape differ from a pure monoexponential decay, due to electron or hole trapping mechanisms taking place in the materials. When the pigments are embedded in dense, scattering media, other light interactions may appear, including scattering, self-absorption or additional non-radiative absorption (heating). For a given pigment concentration, these curves experimentally show a charge saturation effect when the excitation is increased, either by receiving higher intensities or longer exposure times, this process affecting the coefficient of the power-law decay function. The dependence of the emission intensity with the pigment concentration is also shown to produce a saturation effect. The origin of some of these results, obtained from experiments on sintered glass samples with long-life phosphorescent pigments, is explored by means of a multilayer model of photons, where scattering, absorption and emission processes may be governed in each layer and produce an overall reflectance.

Keywords:

• photoluminescent pigments
• sinterized glass
• saturation effects
• afterglow