PHOTOLUMINESCENCE OF NANOPHOSPHORS CaAl2O4:Eu3+ IN A WIDE INTERVAL OF TEMPERATURES AND LEVELS OF LASER EXCITATION

Abstract

We study the spectra of excitation and photoluminescence of CaAl2O4:Eu3+ nanoluminophores in a wide interval of temperatures and laser excitation levels from 40 to 2.3 · 103 kW/cm2. The photoluminescence spectra of CaAl2O4:Eu3+ have the shape of narrow lines and are located in the region 550–750 nm of the visible spectrum. An extremely high stability of the position and shape of the photoluminescence spectra of nanopowders under investigation is established at high levels of laser excitation up to 2.3 · 103 kW/cm2 at a constant luminescence efficiency up to 60 kW/cm2. A further increase in the excitation level leads to a reversible drop in the photoluminescence efficiency. The threshold of an irreversible drop in the luminescence efficiency has not been reached.