| 摘要 |
The proposed low correlated colour temperature phosphor converted LED is characterized by a small non-visual photobiological action to humans, which manifests itself as the suppression of melatonin secretion in the pineal gland, and can be used for the illumination of streets, car parking lots, pedestrian and bicycle tracks, building facades, monuments, parks and house yards that only slightly disrupts the circadian rhythm of humans. The LED has a semiconductor chip that emits short wavelength light in the blue, violet or near UV region due to the injection electroluminescence and a wavelength converter which converts the said short wavelength light due to photoluminescence to longer wavelength light having an orange component with the spectrum peaking in the range of about from 570 nm to 600 nm. In the case of partial conversion LED, the chip generates blue light that is partially converted to orange light by one phosphor (for instance, yttrium magnesium aluminium silicon garnet activated by trivalent cerium ions (Y3Mg2AISi2012:Ce3+), barium strontium silicon nitride activated by divalent europium ions ((Ba,Sr)2Si5N8:Eu2+), barium strontium orthosilicate, activated by divalent europium ions ((Ba,Sr)SiO4:Eu2+), calcium - alpha silicon aluminium oxynitride, activated by divalent europium ions (Ca-α-SiAlON:Eu2+), or calcium strontium selenide, activated by divalent europium ions ((Ca,Sr)Se:Eu2+)) contained in the converter. In the case of complete conversion LED, the chip generates near UV light that is completely absorbed in the converter and converted by a blue phosphor (for instance, CaMgSi2O6:Eu2+, Ba5SiO4Cl6:Eu2+, Mg3Ca3(PO4)4:Eu2+, (Ca,Sr,Ba)5(PO4)3CI :Eu2+, Ca2B5O9(Br,Cl):Eu2+, BaMgAl10O17:Eu2+,Mn2+, BaMg2Al16O27:Eu2+, (Lu,Gd)2SiO5:Ce3+, Sr2P2O7:Sn2+, SrSiAI2O3N2:Ce3+ or La3Si6N11 :Ce3+) and the orange phosphors mentioned above. |
