Speaker
Mr
Setumo Victor Motloung
(University of the Free State (Qwaqwa Campus))
Description
The XRD data revealed that all annealed samples consist of the pure cubic MgAl2O4 structure. The estimated crystallites size were in the range of 12.1 – 11.0 nm in diameter. SEM results showed that the dopant type and varying the Cr3+ concentration in the co-activated samples influences the surface morphology of the phosphor. The PL results showed that the host, 0.1% Cr3+ and Eu3+ activated nanophosphor emits at different wavelengths. Emission peak at 390 nm is attributed to the band-gap defects in the host material. Emission at 405 is attributed to arise from both the contribution from the host and Cr3+ (4T1 → 4A2 transition) emissions. The green emission peak at 565 nm is attributed to arise from either the host or Cr3+ (4T2 → 4A2 transition). An emission peak at 574 nm is attributed to the well-known orange emission from 5D0 → 7F1 transition in Eu3+ ion, while the emission peak at 619 nm is assigned to the Eu3+ electric dipole from 5D0 → 7F2 transition. An emission at 694 nm is attributed to the Cr3+ from 2E → 4A2 transition. Co-activating the host with Cr3+ ion quenches the host emission at 390 nm. The CIE color coordinates (see Fig. 2) shows that the emission color can be turned by varying the co-activator concentration.
Are you currently a postgraduate student? (Yes/No)
Yes
Please provide the name and email address of your supervisor.
Prof Dejene (dejeneBF@qwa.ufs.ac.za)
At what level of studies are you currently? (Hons/MSc/PhD)
PhD
Primary author
Mr
Setumo Victor Motloung
(University of the Free State (Qwaqwa Campus))
Co-authors
Prof.
Francis Dejene
(University of the Free State)
Prof.
Hendrik Swart
(University of the Free State)
Prof.
Odireleng Ntwaeaborwa
(University of the Free State)
