Eu3+-doped fluoro-telluroborate glasses as red-emitting components for W-LEDs application

G. Lakshminarayana, Akshatha Wagh, Sudha D. Kamath, A. Dahshan, H. H. Hegazy, M. Marzec, I. V. Kityk, Dong Eun Lee, Jonghun Yoon, Taejoon Park

Research output: Contribution to journalArticle

Abstract

From 0.1 up to 2.5 mol% Eu3+-doped fluro-telluroborate glasses as red light-emitting components for white-light-emitting diodes (WLEDs) were investigated. Non-periodicity in the atomic arrangements was studied through the XRD pattern. The photoluminescence (PL) spectra were recorded under blue light (464 nm) excitation and analyzed. All the PL spectra exhibit an intense peak at 612 nm for 5D07F2 transition, revealing their red photoemission. Optimal PL emissions were achieved for 1.0 mol% Eu3+-doped sample. The CIE chromaticity coordinates for all the glasses (x = ~0.69, y = ~0.30) fall within the red color region. The J‒O parameters (Ω2, Ω4) were calculated following the emission spectra of Eu3+-doped samples and the intensity parameters (Ω24), as well as the high asymmetry ratio (R/O), indicate the low ionicity in all the studied glasses. Using the J-O parameters, several radiative features like total emission transition probability (AT), branching ratios (radiative (βR) & experimental (βexp)), stimulated emission cross-section (σP E), gain bandwidth (σP E × λeff), and optical gain (σP E × τrad) were evaluated. All the luminescence decay curves fit well to non-exponential function and decay times were decreased at Eu3+ concentration >0.5 mol%. The evaluated σP E = 19.684 × 10−21 cm2, βexp = 0.759, τexp = 1.325 m s, minimum non-radiative relaxation, WNR = 296/s, and 60.78% of quantum efficiency (η) for 1.0 mol% Eu3+-doped glass for 5D07F2 transition indicates its promising features for red light-emitting optical devices and also as a red component in WLEDs.

Original languageEnglish
Article number109555
JournalOptical Materials
DOIs
Publication statusAccepted/In press - 01-01-2019

    Fingerprint

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Computer Science(all)
  • Atomic and Molecular Physics, and Optics
  • Spectroscopy
  • Physical and Theoretical Chemistry
  • Organic Chemistry
  • Inorganic Chemistry
  • Electrical and Electronic Engineering

Cite this

Lakshminarayana, G., Wagh, A., Kamath, S. D., Dahshan, A., Hegazy, H. H., Marzec, M., ... Park, T. (Accepted/In press). Eu3+-doped fluoro-telluroborate glasses as red-emitting components for W-LEDs application. Optical Materials, [109555]. https://doi.org/10.1016/j.optmat.2019.109555