Eu3þ-doped fluoro-telluroborate glasses as red-emitting components for W-LEDs application

Laxminarayana, G and Wagh, Akshatha and Kamath, Sudha D and Dahshan, A and Hegazy, H H and Marzec, M and Kityk, I V and Lee, Dong-Eun and Yoon, Joghun and Park, Taejoon (2019) Eu3þ-doped fluoro-telluroborate glasses as red-emitting components for W-LEDs application. Optical Materials, 99. p. 109555. ISSN 0925-3467

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Abstract

EFrom 0.1 up to 2.5 mol% Eu3þ-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 5D0 → 7F2 transition, revealing their red photoemission. Optimal PL emissions were achieved for 1.0 mol% Eu3þ-doped sample. The CIE chromaticity coordinates for all the glasses (x ¼~0.69, y ¼~0.30) fall within the red color region. The J‒O parameters (Ω2, Ω4) were calculated following the emission spectra of Eu3þ-doped samples and the intensity parameters (Ω2>Ω4), 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 (σE P), gain bandwidth (σE P � λeff), and optical gain (σE P � τrad) were evaluated. All the luminescence decay curves fit well to non-exponential function and decay times were decreased at Eu3þconcentration >0.5 mol%. The evaluated σE P ¼19.684 �10 21 cm2, βexp ¼0.759, τexp ¼1.325 m s, minimum non-radiative relaxation, WNR ¼296/s, and 60.78% of quantum efficiency (ηÞfor 1.0 mol% Eu3þ-doped glass for 5D0 → 7F2 transition indicates its promising features for red light-emitting optical devices and also as a red component in WLEDs.

Item Type: Article
Uncontrolled Keywords: Eu3þ-doped fluoro-telluroborate glasses Luminescence features Radiative properties CIE chromaticity coordinates White LEDs Decay lifetimes
Subjects: Engineering > MIT Manipal > Physics
Depositing User: MIT Library
Date Deposited: 17 Mar 2020 09:48
Last Modified: 17 Mar 2020 09:48
URI: http://eprints.manipal.edu/id/eprint/155007

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