TY - JOUR
T1 - Prediction of Lumen Depreciation and Color Shift for Phosphor-Converted White Light-Emitting Diodes Based on A Spectral Power Distribution Analysis Method
AU - Qian, Cheng
AU - Fan, Jiajie
AU - Fan, Xuejun
AU - Zhang, Guoqi
PY - 2017
Y1 - 2017
N2 - The spectral power distribution (SPD) is considered as the figureprint of a light emitting diode (LED). Based on the analysis on its SPD, a method to predict both lumen depreciation and color shift for the phosphor converted white LEDs (pc-LEDs) is proposed in this paper. First, the entire SPD of a pc-LED is predicted by superimposing two asymmetric double sigmoidal (Asym2sig) models, which represent the decomposed blue light and phosphor converted light peaks, respectively. For a better understanding of how the SPD model affects the photometric and colorimetric characteristics of a pc-LED, a sensitivity study of the SPD parameters is then performed on its luminous flux Φ, color coordinates CIE1976( u′, v′). Second, the evolutionary process of the SPD is predicted for a pc-LED with the color temperature as 3000 K under degradation testing. And based on these predicted SPDs, the drift curves of Φ, u′, v′, and du′ v′are further predicted. Finally, lifetimes of the pc-LED due to lumen depreciation and color shift are estimated simultaneously from the predicted Φ and du′ v′ drift curves.
AB - The spectral power distribution (SPD) is considered as the figureprint of a light emitting diode (LED). Based on the analysis on its SPD, a method to predict both lumen depreciation and color shift for the phosphor converted white LEDs (pc-LEDs) is proposed in this paper. First, the entire SPD of a pc-LED is predicted by superimposing two asymmetric double sigmoidal (Asym2sig) models, which represent the decomposed blue light and phosphor converted light peaks, respectively. For a better understanding of how the SPD model affects the photometric and colorimetric characteristics of a pc-LED, a sensitivity study of the SPD parameters is then performed on its luminous flux Φ, color coordinates CIE1976( u′, v′). Second, the evolutionary process of the SPD is predicted for a pc-LED with the color temperature as 3000 K under degradation testing. And based on these predicted SPDs, the drift curves of Φ, u′, v′, and du′ v′are further predicted. Finally, lifetimes of the pc-LED due to lumen depreciation and color shift are estimated simultaneously from the predicted Φ and du′ v′ drift curves.
KW - Light emitting diodes
KW - prediction methods
KW - semiconductor device reliability
KW - spectral analysis
UR - http://www.scopus.com/inward/record.url?scp=85021844448&partnerID=8YFLogxK
UR - http://resolver.tudelft.nl/uuid:19823cdb-2603-485a-bc51-e9c8edfd9ceb
U2 - 10.1109/ACCESS.2017.2716354
DO - 10.1109/ACCESS.2017.2716354
M3 - Article
AN - SCOPUS:85021844448
SN - 2169-3536
VL - 5
SP - 24054
EP - 24061
JO - IEEE Access
JF - IEEE Access
M1 - 7950923
ER -