Eu^(2+) and Mn^(2+) co-activated CaAlSiN_(3) red phosphors were produced using the solid-state reaction tech⁃nique in a N2 environment.Excitation spectra,emission spectra,and diffuse reflection spectra were used to st...Eu^(2+) and Mn^(2+) co-activated CaAlSiN_(3) red phosphors were produced using the solid-state reaction tech⁃nique in a N2 environment.Excitation spectra,emission spectra,and diffuse reflection spectra were used to study the luminescence characteristics,energy gap,and thermal stability in detail.CaAlSiN_(3)∶Eu^(2+) exhibits an extended emission band when stimulated with 450 nm blue light,which is caused by the 4f65d to 4f7 transition of Eu^(2+).Similar⁃ly,CaAlSiN_(3)∶Mn^(2+) displays a wide emission band centered at 628 nm,which results from Mn^(2+)’s transition from 4T1(4G) to 6A1(6S).When the ions of Mn^(2+)were combined into CaAlSiN_(3)∶Eu^(2+),the photoluminescence intensity of Eu^(2+ )was greatly boosted because there was energy transfer and co-emission between Mn^(2+) and Eu^(2+).Beyond that,CaAlSiN_(3)∶Eu^(2+),Mn^(2+) emerges with splendid thermostability and high quantum efficiency,the quenching temperature surpasses 300℃,and the internal quantum efficiency is determined to be around 84.9%.The white LED was pack⁃aged with a combination of CaAlSiN_(3)∶Eu^(2+),Mn^(2+),LuAG∶Ce3+ and a blue chip.At a warm white-light corresponding color temperature(3009 K) with CIE coordinates(0.4223,0.3748),the color rendering index Ra has reached 93.2.CaAlSiN_(3)∶Eu^(2+),Mn^(2+) would have great application potential as a red-emitting phosphor for white LEDs.展开更多
(Gd,Lu)_(2)O_(3)∶Eu scintillation ceramics have promising applications in the high-energy X-ray imaging.Eu0.1Gd0.6Lu1.3O3 nano-powders with pure phase were prepared from the precursor calcined at 1050℃for 4 h by the...(Gd,Lu)_(2)O_(3)∶Eu scintillation ceramics have promising applications in the high-energy X-ray imaging.Eu0.1Gd0.6Lu1.3O3 nano-powders with pure phase were prepared from the precursor calcined at 1050℃for 4 h by the co-precipitation method.Using the synthesized nano-powders as initial material,Eu_(0.1)Gd_(0.6)Lu_(1.3)O_(3)ceramics were fabri-cated by vacuum pre-sintering at different temperatures for 2 h and hot isostatic pressing(HIP)at 1750℃for 3 h in ar-gon.The influence of pre-sintering temperature on the microstructure,optical and luminescence properties was investi-gated.The Eu_(0.1)Gd_(0.6)Lu_(1.3)O_(3)ceramics pre-sintered at 1625℃for 2 h combined with HIP post-treatment show the high-est in-line transmittance of 75.2%at 611 nm.The photoluminescence(PL)and X-ray excited luminescence(XEL)spectra of the Eu_(0.1)Gd_(0.6)Lu_(1.3)O_(3)transparent ceramics demonstrate a strong red emission peak at 611 nm due to the^(5)D_(0)→^(7)F_(2) transition of Eu^(3+).The PL,PLE and XEL intensities of the HIP post-treated Eu_(0.1)Gd_(0.6)Lu_(1.3)O_(3)ceramics show a trend of first ascending and then descending with the increase of pre-sintering temperature.The thermally stimulated lumines-cence(TSL)curve of the HIP post-treated Eu_(0.1)Gd_(0.6)Lu_(1.3)O_(3)ceramics presents one high peak at 178 K and two peaks with lower intensities at 253 K and 320 K.The peak at 320 K may be related to oxygen vacancies,and the lumines-cence peak at 178 K is related to defects caused by the valence state changes of Eu^(3+)ions.展开更多
文摘Eu^(2+) and Mn^(2+) co-activated CaAlSiN_(3) red phosphors were produced using the solid-state reaction tech⁃nique in a N2 environment.Excitation spectra,emission spectra,and diffuse reflection spectra were used to study the luminescence characteristics,energy gap,and thermal stability in detail.CaAlSiN_(3)∶Eu^(2+) exhibits an extended emission band when stimulated with 450 nm blue light,which is caused by the 4f65d to 4f7 transition of Eu^(2+).Similar⁃ly,CaAlSiN_(3)∶Mn^(2+) displays a wide emission band centered at 628 nm,which results from Mn^(2+)’s transition from 4T1(4G) to 6A1(6S).When the ions of Mn^(2+)were combined into CaAlSiN_(3)∶Eu^(2+),the photoluminescence intensity of Eu^(2+ )was greatly boosted because there was energy transfer and co-emission between Mn^(2+) and Eu^(2+).Beyond that,CaAlSiN_(3)∶Eu^(2+),Mn^(2+) emerges with splendid thermostability and high quantum efficiency,the quenching temperature surpasses 300℃,and the internal quantum efficiency is determined to be around 84.9%.The white LED was pack⁃aged with a combination of CaAlSiN_(3)∶Eu^(2+),Mn^(2+),LuAG∶Ce3+ and a blue chip.At a warm white-light corresponding color temperature(3009 K) with CIE coordinates(0.4223,0.3748),the color rendering index Ra has reached 93.2.CaAlSiN_(3)∶Eu^(2+),Mn^(2+) would have great application potential as a red-emitting phosphor for white LEDs.
文摘(Gd,Lu)_(2)O_(3)∶Eu scintillation ceramics have promising applications in the high-energy X-ray imaging.Eu0.1Gd0.6Lu1.3O3 nano-powders with pure phase were prepared from the precursor calcined at 1050℃for 4 h by the co-precipitation method.Using the synthesized nano-powders as initial material,Eu_(0.1)Gd_(0.6)Lu_(1.3)O_(3)ceramics were fabri-cated by vacuum pre-sintering at different temperatures for 2 h and hot isostatic pressing(HIP)at 1750℃for 3 h in ar-gon.The influence of pre-sintering temperature on the microstructure,optical and luminescence properties was investi-gated.The Eu_(0.1)Gd_(0.6)Lu_(1.3)O_(3)ceramics pre-sintered at 1625℃for 2 h combined with HIP post-treatment show the high-est in-line transmittance of 75.2%at 611 nm.The photoluminescence(PL)and X-ray excited luminescence(XEL)spectra of the Eu_(0.1)Gd_(0.6)Lu_(1.3)O_(3)transparent ceramics demonstrate a strong red emission peak at 611 nm due to the^(5)D_(0)→^(7)F_(2) transition of Eu^(3+).The PL,PLE and XEL intensities of the HIP post-treated Eu_(0.1)Gd_(0.6)Lu_(1.3)O_(3)ceramics show a trend of first ascending and then descending with the increase of pre-sintering temperature.The thermally stimulated lumines-cence(TSL)curve of the HIP post-treated Eu_(0.1)Gd_(0.6)Lu_(1.3)O_(3)ceramics presents one high peak at 178 K and two peaks with lower intensities at 253 K and 320 K.The peak at 320 K may be related to oxygen vacancies,and the lumines-cence peak at 178 K is related to defects caused by the valence state changes of Eu^(3+)ions.
