Study of photoluminescence properties of Er³⁺ ions in SiO₂–GeO₂ and Al₂O₃ nanoparticles

Abstract

We have used the sol–emulsion–gel method to prepare nanoparticles of SiO₂, SiO₂–GeO₂ and Al₂O₃ doped by the same concentration Er³⁺ ions for comparison. We have compared the luminescent efficiencies of these particles and we found that the luminescence spectra and lifetime of the excited state ⁴∣_13/2 of Er³⁺ ions are found to be sensitive to the nature of host. A broad emission spectrum of width 58–55 nm peaked at wavelength of 1.5 μm and the decay times of ⁴∣_13/2→⁴∣ _15/2 transition are 7.57 and 2.07 ms for 1000 °C heat-treated 1.0 mol% Er³⁺ doped SiO₂–GeO₂ and Al₂O₃ nanoparticles, respectively. The analysis suggests that modification of relaxation mechanism is due to the nature of the host.