Cheng-Chien Chen

National Central University

Author Statistics

Papers

Citation

H-Index

i-10 index

Research Trends

Author Order

Document Type

Co-Authors

Tsung‐Hsun Yang

National Central University

Ching-Cherng Sun

National Central University

Ching‐Yi Chen

National Chung Cheng University

Te-Yuan Chung

National Central University

Chih-Yu Chiu

National Central University

Wei-Ting Chien

National Central University

Tsung-Xian Lee

National Central University

Ching-Yi Chen

National Central University

Yu Huan Wang

Shihezi University

Yu-Yu Chang

National Central University

Cooperative Institutions

National Central University

National Yang Ming Chiao Tung University

National Cheng Kung University

Photonics (United States)

National Taiwan University of Science and Technology

National Tsing Hua University

National Dong Hwa University

Chien Hsin University of Science and Technology

National Taiwan University

Taipei Veterans General Hospital

Author Statistics

Papers

Citation

H-Index

i-10 index

Research Field

Packaging efficiency in phosphor-converted white LEDs and its impact to the limit of luminous efficacy

Journal of Solid State Lighting (2014)

Ching-Cherng Sun Yu-Yu Chang Tsung‐Hsun Yang Te-Yuan Chung Cheng-Chien Chen

Abstract In this paper, we start from the study on the packaging efficiency of the phosphor-converted white LED via a new way to measure and calculate the blue light from the blue die to the encapsulation lens. Then we try to estimate the limit of luminous efficacy of a pcW-LED with Type VII structure. In the calculation, with the EQE of 81% of the blue die and Stokes loss, we obtain the optimal limit of luminous efficacy. The largest one reaches 300 lm/W, and occurs for green-white light with CCT from 4000K to 5000K. More practical limit is calculated in considering phosphor quantum loss and geometry loss, and the practical limit of luminous for CRI around 60 is around 210 lm/W, and for CRI larger than 80 is around 175 lm/W. Luminous efficacy will be sacrificed to obtain higher CRI. In order to know the real optical flux on the illuminated target, we introduce the optical utilization factor (OUF). Three application cases are discussed. The OUFs for light bulb, automotive head lamp, and street light are 90%, 60% and 45%, respectively. In considering human factors, it is interesting to find that a light source with lower luminous efficacy can perform higher illumination luminous efficacy (ILE). Therefore it is important to use ILE rather than LE when a light source is practically applied to lighting.

Luminous flux

Luminous efficacy

Color temperature

LED lamp

Luminous intensity

Incandescent light bulb

10.1186/s40539-014-0019-0

Cite

Citations (66)

Light extraction enhancement of GaN-based LEDs through passive/active photon recycling

Optics Communications (2011)

Ching-Cherng Sun Tsung-Xian Lee Yi-Chien Lo Cheng-Chien Chen Shang-Yu Tsai

Active layer

10.1016/j.optcom.2011.06.051

Cite

Citations (25)

Optical Design of a White LED Performing High Spatial Color Uniformity

Frontiers in Optics (2013)

Ching-Cherng Sun Ching-Yi Chen Cheng-Chien Chen Chih-Yu Chiu Yi-Ning Peng

In this paper, a precise simulation and detailed design of angular correlated color temperature (CCT) distribution of white LEDs covering a range of CCT from 2800K to 6500K is presented. In our best knowledge, it is the first time which the kind of research is presented. Besides, for a white LED with the CCT near 6500K, an optimum design of packaging structure with a silicone lens covering a phosphor dome performed an extreme small angular CCT deviation of 105K and 182K in simulation and the corresponding experiment respectively.

Color temperature

10.1364/fio.2013.fth4e.4

Cite

Citations (0)

白光LED封裝效率與可靠性分析之研究;Study of Package Efficiency and Reliability of Phosphor-converted White LED

陳正健 Cheng-Chien Chen

White (mutation)

Source

Cite

Citations (0)

Optical performance as a function of phosphor particle number in white LED

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE (2010)

Cheng-Chien Chen Ching-Yi Chen Wei-Ting Chien Tsung‐Hsun Yang Ching-Cherng Sun

In this paper, we demonstrate a method to calculate the phosphor particle numbers and study the relationship among phosphor particle numbers, light output and correlated color temperature (CCT) of LEDs under remote package type and dispensing package type. We also discuss the influence of the thickness and concentration of phosphors on the performance of LEDs. We compare the various thicknesses and concentrations to check the resultant CCT and the output flux, where we can see that the lumen output is almost equal as the phosphor particle numbers is similar with the CCT at 6500±200 and 5000±100 K under the remote package type.

Luminous flux

Particle (ecology)

10.1117/12.861036

Cite

Citations (2)

Packaging efficiency analysis of phosphor-converted white LEDs

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE (2014)

Ching-Cherng Sun Yu-Yu Chang Cheng-Chien Chen Ching‐Yi Chen Tsung‐Hsun Yang

In this paper, we present our study in packaging efficiency for phosphor-converted white LED (pcW-LED). Then the limit of luminous efficacy of a pcW-LED in different types of packaging is estimated. In the calculation, the EQE of the blue die is assumed 81% and the Stokes loss is counted, we obtain the limit of luminous efficacy, which reaches 300 lm/W, when the color appearance is green-white and the corresponding CCT is between 4000K to 5000K. More consideration for practical limit take consideration of phosphor quantum loss and geometry loss, and the limit of luminous for CRI around 60 is around 240 lm/W, and for CRI larger than 80 is around 175 lm/W.

Luminous efficacy

Quantum Efficiency

Luminous flux

10.1117/12.2063770

Cite

Citations (0)

High uniformity in angular correlated-color-temperature distribution of white LEDs from 2800K to 6500K

Optics Express (2012)

Ching-Cherng Sun Ching‐Yi Chen Cheng-Chien Chen Chih-Yu Chiu Yi-Ning Peng

In this paper, to our best knowledge, it is the first time to present a precise simulation and detailed design of angular correlated color temperature (CCT) distribution of white LEDs covering a range of CCT from 2800K to 6500K. An optimized design of packaging structure with a silicone lens covering a phosphor dome performed an extreme small angular CCT deviation of 105K in the simulation and 182K in a corresponding real sample for a white LED with the CCT near 6500K.

Color temperature

Color rendering index

10.1364/oe.20.006622

Cite

Citations (71)

Essential Factor for Determining Optical Output of Phosphor-Converted LEDs

IEEE photonics journal (2014)

Tsung‐Hsun Yang Cheng-Chien Chen Ching‐Yi Chen Yu-Yu Chang Ching‐Cherng Sun

An essential factor of the particle number is exploited for the phosphor excitation in phosphor-converted white LEDs. The particle number can clearly reveal the dependence of the light output flux and the correlated color temperature upon the conventional parameters, thickness, and concentration of the phosphors in a simpler way. In addition, we also find that there might exist an optimal particle number for the maximal luminous light output. An empirical function is then proposed for successfully modeling the relation between the output light and the particle number.

Luminous flux

Particle (ecology)

Radiant flux

Luminous efficacy

10.1109/jphot.2014.2308630

Cite

Citations (19)

Maintenance of stable light emission in high power LEDs

Microelectronics Reliability (2012)

Hung-Yu Chou Cheng-Chien Chen Tsung‐Hsun Yang

Light emission

Luminous flux

Robustness

LED lamp

10.1016/j.microrel.2012.02.002

Cite

Citations (2)

Planar light source by using side-emitting of GaN die with top and bottom reflector

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE (2012)

Chi-Shou Wu Cheng-Chien Chen Ming-Siou Tsai Tsung-Xian Lee Ching-Cherng Sun

Based on Monte Carlo ray tracing we present a study of GaN die with a reflective layer coated on a p-GaN surface inside the light guide as a planar light source. We simulated the lights extracted from the GaN die implanting pyramid microstructure on the top surface of sapphire or on the top surface of p-GaN. Micro pyramid array with different slanted angle from 5⁰ to 85⁰ is shown to effectively improve the light extraction efficiency. In addition, the pattern sapphire substrate with slanted angle of ten degrees is found to be an effective way to increase the lateral directionality than the surface texture.

Reflector (photography)

Pyramid (geometry)

10.1117/12.929531

Cite

Citations (1)