White light generation from Dy3+-doped ZnO–B2O3–P2O5 glasses

Abstract

Dysprosium doped ZnO–B2O3–P2O5 (ZBP) glasses were prepared by a conventional melt quenching technique in order to study the luminescent properties and their utility for white light emitting diodes (LEDs). X-ray diffraction spectra revealed the amorphous nature of the glass sample. The present glasses were characterized by infrared and Raman spectra to evaluate the vibrational features of the samples. The emission and excitation spectra were reported for the ZBP glasses. Strong blue (484 nm) and yellow (574 nm) emission bands were observed upon various excitations. These two emissions correspond to the F49/2→H615/2 and F49/2→H613/2 transitions of Dy3+ ions, respectively. Combination of these blue and yellow bands gives white light to the naked eye. First time, it was found that ZnO–B2O3–P2O5 glasses efficiently emit white light under 400 and 454 nm excitations, which are nearly match with the emissions of commercial GaN blue LEDs and InGaN LED, respectively. CIE chromaticity coordinates also calculated for Dy3+: ZBP glasses to evaluate the white light emission.