Solid State Lighting Color Shift

Doctoral thesis (2017)

Authors

G. Lu Electronic Components, Technology and Materials - EEMCS
Research Group
Electronic Components, Technology and Materials (EEMCS) (TU Delft)
Copyright: © 2017 G. Lu
DOI: https://doi.org/10.4233/uuid:3a724e0a-4834-458f-af41-60a242052132
Solid state lighting Light emitting diodes LED based Luminaire Color Shift Color Maintenance PMMA Degradation MCPET Degradation Mid-Power LED Package Color Shift Acceleration Color Shift Prediction
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Published Date

26-09-2017

Language

English

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Faculty

Electrical Engineering, Mathematics and Computer Science

Department

Microelectronics

Research Group

Electronic Components, Technology and Materials

Abstract

Luminous flux maintenance and color stability are two important factors to evaluate the lighting quality. Where a significant amount of research efforts are performed on the former and even some standards have been generated for lumen decay acceleration, research activities and achievements on the latter are lagging behind. DOE Energy Star Program requires that the change of chromaticity over the minimum lumen maintenance test period (6000 hours) should be within 0.007 on the CIE 1976 (u', v') diagram. The color shift mechanisms for LED lighting are complex due to its comprehensive structure, generally composed of LED die, phosphor, silicone, reflector, diffusers, and so on, all of which may contribute to the color shift during operation. On top of this, each individual component has its own degradation mechanism. Studies on the LED based luminaire level color shift reliability are little publicly available except some based on the statistical (data-driven) method...