Study on color-tunable phosphor-coated white light-emitting diodes with high S/P ratios
Ziquan Guo,
Tienmo Shih,
Jingjing Xiao,
Hongli Lu,
Yijun Lu,
Tingzhu Wu,
Yue Lin,
Yulin Gao,
Hua Xiao,
Zhong Chen
Affiliations
Ziquan Guo
Department of Electronic Science, Fujian Engineering Research Center for Solid-state Lighting, State Key Laboratory for Physical Chemistry of Solid Surfaces, Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient Devices, Xiamen University, Xiamen, China 361005
Tienmo Shih
Department of Physics, Xiamen University, Xiamen, China 361005
Jingjing Xiao
Department of Electronic Science, Fujian Engineering Research Center for Solid-state Lighting, State Key Laboratory for Physical Chemistry of Solid Surfaces, Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient Devices, Xiamen University, Xiamen, China 361005
Hongli Lu
Department of Electronic Science, Fujian Engineering Research Center for Solid-state Lighting, State Key Laboratory for Physical Chemistry of Solid Surfaces, Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient Devices, Xiamen University, Xiamen, China 361005
Yijun Lu
Department of Electronic Science, Fujian Engineering Research Center for Solid-state Lighting, State Key Laboratory for Physical Chemistry of Solid Surfaces, Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient Devices, Xiamen University, Xiamen, China 361005
Tingzhu Wu
Department of Electronic Science, Fujian Engineering Research Center for Solid-state Lighting, State Key Laboratory for Physical Chemistry of Solid Surfaces, Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient Devices, Xiamen University, Xiamen, China 361005
Yue Lin
Department of Electronic Science, Fujian Engineering Research Center for Solid-state Lighting, State Key Laboratory for Physical Chemistry of Solid Surfaces, Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient Devices, Xiamen University, Xiamen, China 361005
Yulin Gao
Department of Electronic Science, Fujian Engineering Research Center for Solid-state Lighting, State Key Laboratory for Physical Chemistry of Solid Surfaces, Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient Devices, Xiamen University, Xiamen, China 361005
Hua Xiao
Department of Electronic Engineering, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong, Hong Kong
Zhong Chen
Department of Electronic Science, Fujian Engineering Research Center for Solid-state Lighting, State Key Laboratory for Physical Chemistry of Solid Surfaces, Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient Devices, Xiamen University, Xiamen, China 361005
In this study, we have investigated the trade-off between the color rendering index (CRI, Ra) and the scotopic/photopic ratio (S/P) for color-tunable phosphor-coated white light-emitting diodes (LEDs) at two CRI limitations (Ra ≥ 70 and Ra ≥ 96). First, luminescent spectra measurements have been conducted to determine experimental results of Ra and S/P under various correlated color temperatures (CCTs). Then, a nonlinear programming method has been adopted for the optimization of Ra and S/P by varying spectral shapes through adjusting spectral parameters, such as peak wavelengths, full-width at half-maxima, and relative intensities. Therefore, polynomial curves of optimal S/P versus CCT at two Ra limitations have been discovered, enabling users to obtain optimal S/P under arbitrary CCTs within [2700 K, 6500 K]. In addition, a comparison study between the present work and our previous work has also been conducted at Ra = 70, and a fair agreement of optimal S/P has been observed.
