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Studies of Scotopic/Photopic Ratios for Color-Tunable White Light-Emitting Diodes
oleh: Zi-Quan Guo, Tien-Mo Shih, Yi-Jun Lu, Yu-Lin Gao, Li-Hong Zhu, Guo-Long Chen, Ji-Hong Zhang, Si-Qi Lin, Zhong Chen
Format: | Article |
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Diterbitkan: | IEEE 2013-01-01 |
Deskripsi
Three- and four-hump InGaN-based white light-emitting diodes (LEDs) have been computationally investigated. The investigation includes three-hump LEDs precoated with green- and red-emitting quantum dots (QDs) and four-hump LEDs precoated with green-, yellow-, and red-emitting QDs. Results show scotopic/photopic (S/P) ratios <formula formulatype="inline"><tex Notation="TeX">$>$</tex></formula> 3.80 and color rendering indices (CRIs) <formula formulatype="inline"><tex Notation="TeX">$\geq$</tex></formula> 70 for three-hump LEDs and S/P ratios <formula formulatype="inline"><tex Notation="TeX">$>$</tex></formula> 3.90 and CRIs <formula formulatype="inline"><tex Notation="TeX">$\geq$ </tex></formula> 70 for four-hump LEDs under a correlated color temperature (CCT) of 45 000 K. Furthermore, for both three- and four-hump LEDs under the condition of CCT <formula formulatype="inline"><tex Notation="TeX">$>$</tex> </formula> 5000 K, optimal results in this paper exhibit capabilities of exceeding <formula formulatype="inline"> <tex Notation="TeX">$\hbox{S/P} = 2.50$</tex></formula> and simultaneously satisfying the criterion of CRI <formula formulatype="inline"><tex Notation="TeX">$\geq$</tex></formula> 70. Our simulation procedure is conducted under variations of nine CCTs, several wavelengths, and peak heights. Optimized results of S/P ratios and CRIs are identified and retained through filtering off a great number of unqualified candidates. Finally, present findings may help improve the quality of eye visions pertaining to LED illumination and help reduce the electrical energy consumption related to LED usage.