Journal:Journal of Luminescence
Abstract:YAG:Ce3+ yellow phosphor are particularly used luminescent materials to produce white light in phosphorconverted
white LED (pc-WLED). Surface coating of YAG phosphor is the main concern for desired optical
performance of the phosphors. Many scholars conducted various experimental analysis on the surface coating of
phosphors to improve yellow emission, but the theoretical explanation by which phosphor coating could help
improving light efficiency has not yet been studied. In this paper, based on Mie theory, the optical constants such
as scattering coefficient, absorption coefficient and asymmetry parameter of YAG:Ce3+ phosphor and YAG@SiO2
(YAG:Ce3+ phosphor surface coated with nano-SiO2 layer) were calculated. An optical configuration of chip scale
packages (CSP) WLED was constructed by coupling YAG:Ce3+ or YAG@SiO2 phosphors with a LED laser. Based
on the optical parameters calculated by Mie theory, the luminescent properties of YAG:Ce3+ and YAG@SiO2
WLED were simulated by Monte Carlo method. The results showed that a thin SiO2 coating layer on YAG
phosphor result in an overall increase in luminous performances compared with original YAG WLED. The absorption
coefficient of phosphor is the main concern affecting the light emission in WLED. Due to the fact that
YAG@SiO2 possess higher 460 nm absorption coefficient (460μabs), it could absorb more blue light than YAG,
thereby it has a 1.2% higher conversion efficiency than YAG, finally the enhanced luminous efficiency of
YAG@SiO2 WLED is obtained. The results obtained in this work provides a potential method in future WLED
packaging designing.
Indexed by:Journal paper
Volume:244
Page Number:118699
Translation or Not:no
Date of Publication:2021-12-22
Included Journals:SCIE