Effects of Ce3+ concentration, beam voltage and current on the cathodoluminescence intensity of SiO2:Pr3+-Ce3+ nanophosphor

G. H. Mhlongo, O. M. Ntwaeaborwa, M. S. Dhlamini, H. C. Swart, K. T. Hillie

Research output: Contribution to journalArticlepeer-review

9 Citations (Scopus)


SiO2:Pr3+-Ce3+ phosphor powders were successfully prepared using a sol-gel process. The concentration of Pr 3+ was fixed at 0.2 mol% while that of Ce3+ was varied in the range of 0.2-2 mol%. High resolution transmission electron microscopy (HRTEM) clearly showed nanoclusters of Pr and Ce present in the amorphous SiO2 matrix, field emission scanning electron microscopy (FE-SEM) indicated that SiO2 clustered nanoparticles from 20 to 120 nm were obtained. Si-O-Si asymmetric stretching was measured with Fourier transform-IR (FT-IR) spectroscopy and it was also realized that this band increased with incorporation of the activator ions into the SiO2 matrix. The broad blue emission from the Ce3+ ions attributed to the 5d 1-4f1 transition was observed from the SiO2:0.2 mol% Pr3+-1 mol% Ce3+ phosphor. This emission was slightly enhanced compared to that of the singly doped SiO2:1 mol%Ce3+ phosphor. Further investigations were conducted where the CL intensity was measured at different beam voltages and currents from 1 to 5 kV and 8.5 to 30 μA, respectively, in order to study their effects on the CL intensity of SiO2:0.2 mol% Pr3+-1 mol% Ce3+. The electron-beam dissociated the SiO2 and as a result an oxygen-deficient surface dead or non-luminescent layer of SiOx, where x < 2 on the surface, was formed.

Original languageEnglish
Pages (from-to)2986-2992
Number of pages7
JournalJournal of Alloys and Compounds
Issue number6
Publication statusPublished - 10 Feb 2011
Externally publishedYes


  • Cathodoluminescence
  • Degradation
  • Energy transfer

ASJC Scopus subject areas

  • Mechanics of Materials
  • Mechanical Engineering
  • Metals and Alloys
  • Materials Chemistry


Dive into the research topics of 'Effects of Ce3+ concentration, beam voltage and current on the cathodoluminescence intensity of SiO2:Pr3+-Ce3+ nanophosphor'. Together they form a unique fingerprint.

Cite this