Author
Azarifar, Mohammad, Cengiz, Ceren, Arık, Mehmet
Publication Date
2021-03
Publication Place
-
Elsevier
Subject
Phosphor, Stokes shift, Pc-LED, Self-heating, Thermal management
Type
Periodical
Language
English
Digital
Yes
Manuscript
No
Library
Özyeğin University
Library Asset ID
0022-2313
Record ID
e705ad74-98c5-46dc-b149-9357df1e8b36
Library Location
Mechanical Engineering
Date
2021-03
Sample Text
Since 2003, self-heating effect of phosphor which reduces the efficacy and reliability of phosphor conversion (Pc) light emitting diodes (LEDs), has been a growing research area of opto-thermal Pc-LED modeling. However, few studies have focused on the particles based nature of the phosphor self-heating. Based on a new approach, accurate Monte Carlo ray tracing simulations are performed in regions of interest over discretized control volumes where only a single phosphor particle is exposed to the light radiation. Governed by the Mie scattering effects, heat generation values of phosphor particles showed strong dependency on their optical and geometrical properties. Additionally, based on the emissive behavior of the LED, space above the LED can be divided into two irradiance levels; near and far scale regions. In near scale region, where irradiance levels are above 0.1 W/mm(2), phosphor particles exhibited significant self-heating in milli-Watt scale values. Derived self-heating values are imported to simplified thermal models where phosphor particles showed a temperature rise in excess of 100 degrees C more than LED chip which can lead to considerable conversion efficiency loss and a reduction in lifetime. Higher temperatures are expected in higher irradiance levels where matrix material carbonization can also occur causing fire hazards.
DOI
10.1016/j.jlumin.2020.117782
Cilt
231
