Materials Research Bulletin, Vol.72, 168-175, 2015
White light emission and effect of annealing on the Ho3+-Yb3+ codoped BaCa2Al8O15 phosphor
The BaCa2Al8O15 (BcAo) phosphors codoped with suitable Ho3+-Yb3+ dopant concentration prepared by combustion method illuminate an intense white light upon near infrared diode laser excitation. The structural analysis of the phosphors and the detection of impurity contents have been performed by using the X-Ray Diffraction, FESEM and FTIR analysis. The purity of white light emitted from the sample has been confirmed by the CIE chromaticity diagram. Also, the white light emitted from the sample persists with the variation of pump power density. The phosphors emit upconversion (UC) emission bands in the blue, green and red region (three primary colours required for white light emission) along with one more band in the near infrared region of the electromagnetic spectrum. On annealing the white light emitting sample at higher temperatures, the sample starts to emit green colour and also the intensity of green and red UC emission bands get enhanced largely. (C) 2015 Elsevier Ltd. All rights reserved.
Keywords:Inorganic compounds;Chemical synthesis;X-ray diffraction;Infrared;Spectroscopy;Optical properties;Phosphors