Speaker
Ms
Mantwa Annah Lephoto
(University of the Free State (QwaQwa campus), Private Bag X13, Phuthaditjhaba, 9866, South Africa)
Description
Key words: Combustion method; William-Hall; Band-gap; Photoluminescence; CIE.
Abstract: BaB8O13: Ce3+ powder phosphors were synthesized by solution combustion method for general lighting applications. X-ray diffraction, Fourier transform spectroscopy, Scanning electron microscopy, UV-visible spectroscopy and photoluminescence studies were used to characterize the prepared powder phosphors. Powder X-ray spectra confirmed the formation of orthorhombic structure of BaB8O13 with cell parameters a = 8.550 Å, b = 17.350 Å and c = 13.211 Å according to JCPDS file no: 20-0097 [1]. The estimated crystallite sizes of the powder phosphors from Scherrer’s equation and Hall-Williamson’s plot were in the nanometre scale. Scanning electron microscopy micrographs showed that the particles with irregular shapes were agglomerated together. The bands in the Fourier transform infrared spectra in the range 650 – 1600 cm-1 also confirms the formation of the desired powder phosphor. The estimated bandgap of the powder phosphors from Kubelka - Munk was reduced with the increase in concentration of Ce3+. The BaB8O13: Ce3+ powder phosphors showed emission at around 515 nm ascribed to 5d1 – 4f1 transition of Ce3+ after UV excitation of 270 nm using a monochromatized xenon lamp. A standard CIE diagram derived from relative emissions from the powder phosphors suggested a unique emission concentrated in the green region, thus the phosphor serve as a potential source of green light emitting devices [1].
Reference: 1] E, Erdogomus, E. Orkmaz and V.E. Kafadar, J. Appl. Spectrosc, 80, 2014, 952-956
Apply to be<br> considered for a student <br> award (Yes / No)?
Yes
Summary
N/A
Level for award<br> (Hons, MSc, <br> PhD, N/A)?
PhD
Main supervisor (name and email)<br>and his / her institution
Ntwaeaborwa Martin
ntwaeab@gmail.com
Witwatersrand university
School of physics, University of the Witwatersrand, Private Bag 3, Wits, 2050, South Africa
Would you like to <br> submit a short paper <br> for the Conference <br> Proceedings (Yes / No)?
Yes
Primary author
Ms
Mantwa Annah Lephoto
(University of the Free State (QwaQwa campus), Private Bag X13, Phuthaditjhaba, 9866, South Africa)
Co-authors
Dr
Kamohelo George Tshabalala
(University of the Free State (QwaQwa campus), Private Bag X13, Phuthaditjhaba, 9866, South Africa)
Prof.
Odireleng Martin Ntwaeaborwa
(University of the Witwatersrand, Private Bag 3, Wits, 2050, South Africa)
Mr
Selepe Joel Motloung
(University of the Free State (QwaQwa campus), Private Bag X13, Phuthaditjhaba, 9866, South Africa)
