Analysis and Modeling of Optical and Thermal Properties of Phosphor Converted White Light Emitting Diode

Shen, Xuehua; Chen, Hong; Lin, Jie; Li, Yan; Lin, Huichuan; Chen, Jingdong; Chen, Cihai

doi:10.1109/access.2019.2936593

Cited by 4 publications

(5 citation statements)

References 23 publications

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“…Within the mixed white light emitted from PC-WLEDs, define P opt,y(w) and P opt,b(w) , respectively, as the optical power of the yellow spectrum and the optical power of the blue spectrum, and the ratio between them is P opt,y(w) /P opt,b(w) . A particular relationship has been confirmed to exist between the ratio P opt,y(w) /P opt,b(w) of PC-WLEDs and the ratio P opt,p /P opt,e of YAG:Ce 3+ phosphors [31], namely…”

Section: Modeling With Phosphor Excitation Characteristicsmentioning

confidence: 86%

Measurement model of circadian action factor of phosphor-converted white LEDs based on photometric, electrical, and thermal properties

Shen,

Chen,

et al. 2024

Metrologia

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Light stimulus is confirmed to have critical non-visual biological effects on human beings, and thus evaluation of lighting quality should not be limited to traditional visual performance. The circadian action factor (CAF) has been put forward to quantify such non-visual effects of light sources. This paper focuses on studying the photometric, electrical, and thermal properties of widely used phosphor-converted white LEDs (PC-WLEDs), and establishes an indirect measurement model of CAF regarding temperature, current and excitation wavelength. During modeling, the spectral power distribution (SPD) of PC-WLEDs is described as an extended Gaussian function of the double-color (blue-yellow) spectrum. In verifications, the remarkable consistency is obtained between indirect measurements and direct calculations, while the maximum relative errors do not exceed 2.6% and the mean relative errors do not exceed 0.9%. The proposed measurement model involves a series of optical tests and calibrations, which are simple for LED system designers to comply with. It offers an effective tool to quantify the PC-WLEDs’ non-visual biological effects on human beings, avoiding costly optical instruments and laborious calculations. Furthermore, it provides a potential theoretical foundation for realizing human-centric assessment, regulation and control of artificial lighting.

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Section: Modeling With Phosphor Excitation Characteristicsmentioning

confidence: 86%

Measurement model of circadian action factor of phosphor-converted white LEDs based on photometric, electrical, and thermal properties

Shen,

Chen,

et al. 2024

Metrologia

Self Cite

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“…It should be noted, that two varying Pearson type VII models were found in the literature. Therefor, both implementation by Reifegerste et al [4] and LMFIT built-in [19] [4], [5], [9], [10], [16], [21] Logistic Power Peak A, λp, σ S ∈ [10 −15 , 100]…”

Section: B Implementationmentioning

confidence: 99%

Advancements in Spectral Power Distribution Modeling of Light-Emitting Diodes

et al. 2022

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The unique radiative, photometric and colorimetric characteristic of a light-emitting diode is derived from its spectral power distribution. Modeling such characteristics with respect to the forward current, temperature or operating time has been subject of various studies. Deriving a simple analytical model, however, is not trivial due to the unique emission pattern varying with different types and technologies of light emitting diodes. For this purpose, curve fitting multiple superimposed Gaussian probability density functions to the spectral power distribution is a common approach. Despite very a high R 2 goodness of fit results, significant deviations within the photometric and colorimetric parameters, such as luminous flux or chromaticity coordinates, are observed. In addition, most studies were conducted on a small sample set of very few different spectral power distributions. This work provides a comprehensive comparison and evaluation of 19 different (superimposed) probability density function based models provided by the literature tested on a total of 15 different spectral power distributions of monochromatic blue, green and red light-emitting diode as well as phosphor-converted spectra of lime, purple and different correlated color temperature types white samples. All models were evaluated by means of their coefficient of determination, radiant flux, chromaticity coordinate deviation and Bayesian Information Criterion. This study shows that a superimposed (split) Pearson VII model is able to outperform the commonly used Gaussian model approach by far. In addition, an application example in regard of forward current dependence is given to prove the proposed approach.

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“…This type of input enables smaller capacitance filter values, which allow the use of more reliable technologies compared to electrolytic capacitors (such as film capacitors). In addition to these models, Shen et al included the effects of phosphor temperature in a PET model, showing that a good thermal design considering this aspect is capital to maintain performance in White LED (WLED) devices [16]. Unlike Shen et al, a dynamic PET analysis was carried out by Hui, Lee, and Tan in [17].…”

Section: Related Workmentioning

confidence: 99%

Effect of Temperature on Channel Compensation in Optical Camera Communication

et al. 2021

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General-purpose Complementary Metal Oxide Semiconductor (CMOS) sensors perform the image desegregation in three channels (red, green, and blue) as a result of a band-pass wavelength filtering carried out using Foveon or Bayer filters. This characteristic can be used in Optical Camera Communication (OCC) systems for increasing the links’ data rate by introducing Wavelength Division Multiplexing (WDM) or Color Shift Keying (CSK) modulation schemes. However, these techniques need a compensation stage to mitigate the cross-talk between channels introduced by the filters. This compensation is performed by a Channel State Information (CSI) estimation and a zero-forcing compensation scheme. The impact of the temperature effects of light-emitting diode (LED) emissions on the zero-forcing compensation scheme’s performance has not been analyzed in depth. This work presents a comprehensive methodology and experimental characterization of this impact for Foveon and Bayer-based image sensors, assuming that the CSI is estimated under temperature conditions different from the LED’s stationary temperature regime. Besides, Signal-to-Interference-plus-Noise Ratio (SINR) and Bit Error Rate (BER) performance metrics are presented in order to estimate the repercussion in an OCC link. The results reveal that the Foveon sensor obtains more unsatisfactory performance than the Bayer-based sensor. On the other hand, the blue band is the most penalized by the thermal effect.

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Analysis and Modeling of Optical and Thermal Properties of Phosphor Converted White Light Emitting Diode

Cited by 4 publications

References 23 publications

Measurement model of circadian action factor of phosphor-converted white LEDs based on photometric, electrical, and thermal properties

Measurement model of circadian action factor of phosphor-converted white LEDs based on photometric, electrical, and thermal properties

Advancements in Spectral Power Distribution Modeling of Light-Emitting Diodes

Effect of Temperature on Channel Compensation in Optical Camera Communication

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