Open AccessPore characteristics for improving luminous efficacy of phosphor-in-glass
Author(s) -
Sunil Kim,
H. Yie,
Seunggon Choi,
Aram Sung,
Hyung Sun Kim
Publication year - 2015
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.23.0a1499
Subject(s) - materials science , phosphor , sintering , luminous efficacy , light scattering , viscosity , porosity , scattering , composite material , optics , luminescence , optoelectronics , layer (electronics) , physics
Pores formed during the sintering of a glass/phosphor mixture affect the scattering and path of light within the resulting phosphor-in-glass (PIG) plate. An investigation of the interactions between blue light from an LED chip and pores within a PIG plate is therefore needed to understand the effect of light scattering on the optical properties. To this end, various glass compositions based on SiO 2 -B 2 O 3 -ZnO were prepared so as to better understand the effect of modifiers (i.e., Li 2 O, Na 2 O, La 2 O 3 , WO 3 ) on the viscosity and pore properties at different sintering temperatures. This study found that PIGs sintered within a given viscosity range exhibit different optical properties depending on their pore size and overall porosity; a higher luminous efficacy observed in the case of intermediate scattering length values was due to an improved interaction between pores and light. This is a significant finding, as ensuring suitable PIG pore characteristics is an important factor in achieving a desired spectrum and high efficacy from white LEDs.