Heavy metal oxide glass responses for white light emission

Abstract

Rare-earth-doped heavy metal oxide glasses (HMOG) have attracted much interest due to their wide range of applications in the field of optoelectronic devices. The current study focuses on the preparation of undoped and Dy2O3-doped heavy metal oxide glass that is mainly based on non-conventional glass formers PbO and Bi2O3 together with TeO2 and B2O3 glass forming oxides. The amorphous nature of the obtained glasses were confirmed by x-ray diffraction (XRD) measurements. The glasses were evaluated through optical absorption in ultraviolet–visible and near-infrared (UV–VIS–NIR) regions, photoluminescence, Fourier transform infrared (FTIR), and density measurements. The absorption spectra of undoped glass revealed a characteristic recorded peaks located in the UV and Near-Vis region while extended peaks in the visible and Near-IR region were detected after Dy2O3 additions. The luminescence spectra revealed a characteristic blue, yellow, and red emissions with a very weak emission in NIR region. The chromaticity coordinates (CIE) were evaluated from the emission spectra and revealed the suitability of HMOG for white light-emitting diode (LED) applications. The measured density and the calculated optical parameters (Eopt, ∆E, and n) were correlated with the rare-earth ion concentration. The structural building units of HMOG network were investigated via the FTIR technique. The characteristic vibrational modes of FTIR were observed due to the contribution of PbO4 and BiO6 as a forming building units besides BO4, BO3, and TeO3 units with no extended effect on the vibrational modes after the minor additions of Dy2O3.