標題: Sr8MgGd(PO4)(7):Eu2+: yellow-emitting phosphor for application in near-ultraviolet-emitting diode based white-light LEDs
作者: Huang, Chien-Hao
Wang, De-Yin
Chiu, Yi-Chen
Yeh, Yao-Tsung
Chen, Teng-Ming
應用化學系
Department of Applied Chemistry
公開日期: 2012
摘要: The yellow-emitting phosphor Sr8MgGd(PO4)(7):xEu(2+) (SMGP:xEu(2+)) was successfully synthesized by a solid-state reaction and used for the first time to fabricate white light-emitting diodes (LEDs) with excellent color rendering index (CRI). Furthermore, the luminescence properties' reflectance spectra and fabricated LEDs were firstly investigated. The excitation and reflectance spectra of this phosphor show broad band excitation and absorption in the 240-470 nm near ultraviolet (NUV) region, indicating its potential application in NUV diode based white-light LEDs. Upon excitation at 385 nm, the Eu2+ doped SMGP phosphors showed strong yellow emission centered at 512 and 606 nm, which could be ascribed to the 4f(6)5d(1) -> 4f(7) transitions of Eu2+. The optimal doping concentration of Eu2+ in SMGP was determined to be 0.01 mol. Non-radiative transitions between the Eu2+ ions in the SMGP host were demonstrated to be attributable to dipole-dipole interactions. A white-light NUV LED was fabricated using a phosphor blend of SMGP:0.01Eu(2+) and BAM:Eu2+ pumped by a 385 nm NUV chip, driven by a 350 mA current. The color, chromaticity coordinates (x, y), correlated color temperature (CCT) and Commission Internationale de l'Eclairage (CIE) coordinates can be tuned from yellow ((0.442, 0.481), 3456 K, 75.4) through warm white-light ((0.350, 0.348), 4804 K, 95.6) and eventually to white-light ((0.331, 0.321), 5592 K, 94.1) by weight ratio tuning of the SMGP:0.01Eu(2+) and BAM:Eu2+ phosphors, and the luminous efficacy between 9.6 to 7.6 lm W-1. We are currently evaluating the potential applications of SMGP: xEu(2+) as a yellow-emitting near-ultraviolet (NUV) convertible phosphor in fabricating warm white-light LEDs with excellent CRI.
URI: http://hdl.handle.net/11536/16980
http://dx.doi.org/10.1039/c2ra20646c
ISSN: 2046-2069
DOI: 10.1039/c2ra20646c
期刊: RSC ADVANCES
Volume: 2
Issue: 24
起始頁: 9130
結束頁: 9134
Appears in Collections:Articles


Files in This Item:

  1. 000308824600037.pdf