Print Email Facebook Twitter Color Shift Failure Prediction for Phosphor-Converted White LEDs by Modeling Features of Spectral Power Distribution with a Nonlinear Filter Approach Title Color Shift Failure Prediction for Phosphor-Converted White LEDs by Modeling Features of Spectral Power Distribution with a Nonlinear Filter Approach Author Fan, Jiajie (Hohai University; Beijing Research Center; Changzhou Institute of Technology Research for Solid State Lighting) Mohamed, Moumouni Guero (Hohai University) Qian, Cheng (Changzhou Institute of Technology Research for Solid State Lighting) Fan, Xuejun (Lamar University; Changzhou Institute of Technology Research for Solid State Lighting) Zhang, Kouchi (TU Delft Electronic Components, Technology and Materials; Changzhou Institute of Technology Research for Solid State Lighting; Beijing Research Center) Pecht, Micheal (University of Maryland) Date 2017 Abstract With the expanding application of light-emitting diodes (LEDs), the color quality of white LEDs has attracted much attention in several color-sensitive application fields, such as museum lighting, healthcare lighting and displays. Reliability concerns for white LEDs are changing from the luminous efficiency to color quality. However, most of the current available research on the reliability of LEDs is still focused on luminous flux depreciation rather than color shift failure. The spectral power distribution (SPD), defined as the radiant power distribution emitted by a light source at a range of visible wavelength, contains the most fundamental luminescence mechanisms of a light source. SPD is used as the quantitative inference of an LED's optical characteristics, including color coordinates that are widely used to represent the color shift process. Thus, to model the color shift failure of white LEDs during aging, this paper first extracts the features of an SPD, representing the characteristics of blue LED chips and phosphors, by multi-peak curve-fitting and modeling them with statistical functions. Then, because the shift processes of extracted features in aged LEDs are always nonlinear, a nonlinear state-space model is then developed to predict the color shift failure time within a self-adaptive particle filter framework. The results show that: (1) the failure mechanisms of LEDs can be identified by analyzing the extracted features of SPD with statistical curve-fitting and (2) the developed method can dynamically and accurately predict the color coordinates, correlated color temperatures (CCTs), and color rendering indexes (CRIs) of phosphor-converted (pc)-white LEDs, and also can estimate the residual color life Subject LEDscolor shift failurenonlinear filterreliability and failure analysisspectral power distribution To reference this document use: http://resolver.tudelft.nl/uuid:232f25dd-724e-42e1-a0ec-050dd880da54 DOI https://doi.org/10.3390/ma10070819 ISSN 1996-1944 Source Materials, 10 (7), 1-16 Part of collection Institutional Repository Document type journal article Rights © 2017 Jiajie Fan, Moumouni Guero Mohamed, Cheng Qian, Xuejun Fan, Kouchi Zhang, Micheal Pecht Files PDF materials_10_00819_v2.pdf 4.94 MB Close viewer /islandora/object/uuid:232f25dd-724e-42e1-a0ec-050dd880da54/datastream/OBJ/view