yb^3＋：Er^3＋ co-doped oxy-fluoride ceramics glass has been prepared. The mechanism of up-conversion emissions about Er^3＋ was discussed, and the temperature properties of green up-conversion fluorescence between 30...yb^3＋：Er^3＋ co-doped oxy-fluoride ceramics glass has been prepared. The mechanism of up-conversion emissions about Er^3＋ was discussed, and the temperature properties of green up-conversion fluorescence between 303 and 823 K were investigated. The results show that the sensitivity of this sample reaches its maximum value, about 0.0047 K^-1, when the temperature is 383 K, indicating that this kind of sample can be used as high temperature and high sensitivity optical temperature sensor.展开更多
Er^3 ＋/Yb^3 ＋ phosphate glasses were fabricated. According to McCumber theory, the stimulated emission cross-section of Er^3＋ ions at 1533 nm was calculated on the basis of absorption spectrum, and 0.84 × 10^-...Er^3 ＋/Yb^3 ＋ phosphate glasses were fabricated. According to McCumber theory, the stimulated emission cross-section of Er^3＋ ions at 1533 nm was calculated on the basis of absorption spectrum, and 0.84 × 10^-20 cm^2 is derived, the fluorescence lifetime of ^4I13/2 level is 8.5 ms. An Er^3＋/Yb^3＋ co-doped phosphate glass CW laser pumped by LD was demonstrated at room temperature. The maximum output power is 80 mW and slope efficiency is 16.5%.展开更多
The Er^3＋/yb^3＋ co-doped transparent oxyfluoride glass-ceramics containing CaF2 nano-crystals were successfully prepared. After heat treatments, transmission electron microscopy （TEM） images showed that CaF2 nano-...The Er^3＋/yb^3＋ co-doped transparent oxyfluoride glass-ceramics containing CaF2 nano-crystals were successfully prepared. After heat treatments, transmission electron microscopy （TEM） images showed that CaF2 nano-crystals of 20-30 nm in diameter precipitated uniformly in the glass matrix. luminescence of Er^3＋ at 540 nm and 658 nm was observed in Comparing with the host glass, high efficiency upconversion the glass ceramics under the excitation of 980 nm. Moreover, the size of the precipitated nano-crystals can be controlled by heat-treatment temperature and time. With the increase of the nano-crystal size, the intensity of the red emission increased more rapidly than that of the green emission. The energy transfer process of Er^3＋ and Yb^3＋ was convinced and the possible mechanism of Er^3＋ up-conversion was discussed.展开更多
The photoluminescence （PL） characteristics of Eu^3＋ and Li^＋ co-doped ZnO PL materials against heat-treatment temperature were discussed. The PL xerogel and powder samples were prepared by solgel process. The emis...The photoluminescence （PL） characteristics of Eu^3＋ and Li^＋ co-doped ZnO PL materials against heat-treatment temperature were discussed. The PL xerogel and powder samples were prepared by solgel process. The emission spectra of all samples showed two broad bands peaking at 590 nm and 620 nm under UV-Vis excitation. But the relative intensity of red PL （620 nm） was much greater than that of green PL （590 nm） of the same sample, that s to say, the red color was the main luminescence. With heat-treatment temperature increase, the two kinds of colors PL intensity decreased, and both the red and green PL intensity of the xerogel samples was much greater than those of powder samples respectively. The XRD patterns revealed that Eu^3＋ ions were successfully incorporated in ZnO crystals in xerogel samples. When heat-treatment temperature reached 350 ℃, the Eu^3＋ began to separate out of the ZnO crystals and Eu2O3 crystals came into being. When the powder sample was subjected to UV-Vis excitation, the energy transfered from the host ZnO emission to Eu^3＋ became weaker than the xerogel sample.展开更多
Er3+-Yb3+ co-doped fiber of 2 m long is used as the laser gain medium. Two fiber lasers with different structures have been set up, one is the line cavity fiber laser with the dielectric mirror being replaced by an al...Er3+-Yb3+ co-doped fiber of 2 m long is used as the laser gain medium. Two fiber lasers with different structures have been set up, one is the line cavity fiber laser with the dielectric mirror being replaced by an all-fiber reflecting mirror,the other is the ring cavity all-fiber laser. Both set-ups have achieved lasing operation at the wavelength of 1.53 μm. Pumped by the 1 064 nm light from all-solid-state Nd ∶YAG laser, the two fiber lasers at 1 530 nm are operational. Their output powers are 7.8 mW and 2 mW with 130 mW and 160 mW pump powers.展开更多
Yb^3＋：Er^3＋：Tm^3＋co-doped borosilicate glasses are prepared. Their strong up-conversion photoluminescence spectra in a range from ultra-violet to near-infrared, which are excited by a 978-nm laser diode, are meas...Yb^3＋：Er^3＋：Tm^3＋co-doped borosilicate glasses are prepared. Their strong up-conversion photoluminescence spectra in a range from ultra-violet to near-infrared, which are excited by a 978-nm laser diode, are measured, and the mechanisms of energy transfer among Yb^3＋ Er^3＋ and Tm^3＋ ions are discussed. The results show that there is an unexpected wavelength at 900-nm emission from Yb^3＋ Stark splitting levels to pump Tm^3＋ ions and there exists an optimum pump power. The concentration of the Tm^3＋ dopant gives rise to a prominent effect on the intensity of visible and near-infrared emissions for the yb^3＋：Er^3＋：Tm^3＋ co-doped borosilicate glasses.展开更多
An all-fiber based Er~ 3+ ∶Yb~ 3+ co-doped double clad fiber laser operating at 1550nm is demonstrated. By using 9m long Er~ 3+ ∶Yb~ 3+ co-doped fiber(EYDF) as the gain medium, and using a pair of fiber Bragg gratin...An all-fiber based Er~ 3+ ∶Yb~ 3+ co-doped double clad fiber laser operating at 1550nm is demonstrated. By using 9m long Er~ 3+ ∶Yb~ 3+ co-doped fiber(EYDF) as the gain medium, and using a pair of fiber Bragg gratings as wavelength filters, the line-width of the output laser is as narrow as 0.2nm and the output power is more than 6mW. The fluorescent effect of the laser before its emission is also studied. And it is found that the Er~ 3+ ∶Yb~ 3+ co-doped double-clad fiber laser also exhibits a high gain for Yb~ 3+ transition near 1080nm.展开更多
Based on propagation-rate equations, the influence of different input pulse durations on the properties of Er^3＋/Yb^3＋ co-doped double-clad fiber amplifier at dynamic equilibrium was analyzed. The change characteris...Based on propagation-rate equations, the influence of different input pulse durations on the properties of Er^3＋/Yb^3＋ co-doped double-clad fiber amplifier at dynamic equilibrium was analyzed. The change characteristic of output power sag with pulse duration and repetition rate was shown. Whether single or multichannel input pulses are amplified, the shorter the input pulse duration is, the smaller the power sags of output pulse will be. At low repetition rate, upper gain values（Gupper） of gain swing are almost the same for different input pulse durations, which tend to the small signal gain, but lower gain value（Glower） of short input pulse is larger than that of long input pulse. At highrepetition rate, lower gain value（Glower） approaches to upper gain value（Glower）.展开更多
The growth of LiNbO3 single crystal with Er^3＋ and Zn^2＋ co-doped using Bridgman method and its characteristic absorption spectra and fluorescence spectra were reported. Large-size crystals initially containing Zn^2...The growth of LiNbO3 single crystal with Er^3＋ and Zn^2＋ co-doped using Bridgman method and its characteristic absorption spectra and fluorescence spectra were reported. Large-size crystals initially containing Zn^2＋ （3%） and Er^3＋ （0.6%） with good optical quality were obtained using optimized conditions such as a growth rate of 0.8- 1.5 mm·h^-1 and a temperature gradient of about 30 - 35℃·cm^-1 across the solid-liquid interface and the sealed platinum crucible. X-ray diffraction and differential thermal analysis （DTA） were used to characterize the crystals. The results indicate that the concentration of Er^3＋ ions in crystals, their absorption intensity, and their fluorescence intensity decrease from the bottom to the top in the crystals. However, for the upper part of the crystal, the up-conversion fluorescence intensity is higher than that of the lower part excited by an 800 or 970 nm pump. The effects of the crystal lattice, their structural defect and their effective segregation of Er^3＋ ions were discussed with respect to the variations of the up-conversion fluorescence intensity.展开更多
The growth of LiNbO3 single crystal with Er^3＋/Zn^2＋ co-doped by the bridgman method and the characteristics of absorption spectra and fluorescence spectra were reported. By means of the optimized con- ditions such ...The growth of LiNbO3 single crystal with Er^3＋/Zn^2＋ co-doped by the bridgman method and the characteristics of absorption spectra and fluorescence spectra were reported. By means of the optimized con- ditions such as growth rate of 0.8 - 1.5 mm · h^- 1, temperature gradient about 30 - 35℃ ·cm^-1 across the solid-liquid interface and sealed platinum, large size crystals containing Zn^2＋ （3%） and Er^3＋ （0.6%） with good optical quality were obtained. X-ray diffraction and DTA were used to characterize the crystals. The results indicate that the concentration of Er^3＋ ions in crystals decrease along the growth direction, the absorption intensity and the fluorescence intensity ions also decrease along the growth direction. of Er^3＋ However, for the upper part crystal, the upconversion fluorescence intensity is higher than that of the lower part crystal excited with 800 or 970 nm pump. The effects of crystal lattice, structure defect and effective segregation of Er^3＋ ions were discussed in respect to the variations were discussed of upconversion fluorescence intensity.展开更多
The Er3＋/yb3＋ co-doped phosphate （EYDP） glass waveguides operated at 1539 nm have been manufactured by using the implantation technique of carbon ions under the condition of 6.0 MeV energy and 5.0 × 10^13 ion...The Er3＋/yb3＋ co-doped phosphate （EYDP） glass waveguides operated at 1539 nm have been manufactured by using the implantation technique of carbon ions under the condition of 6.0 MeV energy and 5.0 × 10^13 ions/cm2 fluence in this work. The ion implantation process was computed by means of the stopping and range of ions in matter. The dark-mode spectrum at 1539 nm of the waveguide was recorded by the method of the prism coupling measurement. The microscopic image of the fabricated structure was photographed by an optical microscope. It is the first step for the application of the waveguides on the base of EYDP glasses in optical- integrated photonic devices at near-infrared band.展开更多
A detailed study of the fluorescence emission properties and energy transfer mechanism in Er^（3＋）/Tm^（3＋） co-doped lead silicate glasses was reported. Enhanced near infrared 1.8 μm and visible up-conversion emi...A detailed study of the fluorescence emission properties and energy transfer mechanism in Er^（3＋）/Tm^（3＋） co-doped lead silicate glasses was reported. Enhanced near infrared 1.8 μm and visible up-conversion emissions were investigated under 808 and 980 nm excitations, respectively. The energy transfer mechanism between Er^（3＋） and Tm^（3＋） was analyzed according to the absorption spectra, the emission spectra and the level structures of Er^（3＋） and Tm^（3＋）. The energy transfer efficiency between Er^（3＋） and Tm^（3＋） reached 68.1% in the Er^（3＋）/Tm^（3＋） co-doped lead silicate glasses when pumped by 808 nm laser diode. Based on the absorption spectra, the Judd-Ofelt parameters, spontaneous emission probability, absorption and emission cross sections, gain coefficients were calculated and analyzed. It was found that the calculated emission cross section and the maximum gain coefficient around 1.8 μm were 4.9×10^（–21）cm^2 and 1.12 cm^（–1）, respectively. These results indicated that the Er^（3＋）/Tm^（3＋） co-doped lead-silicate glasses had potential application in near infrared lasers.展开更多
BiOCl crystal shows potential as efficient optical host due to its special layered structure. Here,the luminescence properties of the Er^3＋/Sm^3＋ co-doped BiOCl phosphors as single-phase phosphors were reported. Upo...BiOCl crystal shows potential as efficient optical host due to its special layered structure. Here,the luminescence properties of the Er^3＋/Sm^3＋ co-doped BiOCl phosphors as single-phase phosphors were reported. Upon near ultraviolet excitation（NUV, 380 nm corresponding the ^4 I15/2→ ^4 G11/2 transition of Er^3＋ ions）, the phosphors exhibit the efficient characteristic emissions of Er^3＋ and Sm^3＋ ions simultaneously. The energy transfer（ET） from Er^3＋ to Sm^3＋ ions in the layered crystals has been validated by the variation of emission intensities and decay lifetimes respectively, which is ascribed to be a dipoledipole interaction. By virtue of the ET behavior and increasing Sm^3＋ ion concentration, the enhancing emission intensity of Sm^3＋ and the tunability of emission color from yellowish-green（0.318, 0.420） to white（0.343, 0.347） are realized. The results of our work indicate that the Er^3＋/Sm^3＋ co-doped BiOCI phosphor has a promising application serving as single component white emitting phosphors for NUV excited WLEDs.展开更多
Er^3＋/Yb^3＋ co-doped SrY2O4 phosphors with high color purity and brightness were successfully synthesized via a solid-state reaction method.Luminescence spectrum studies showed that the main red peaks and the minor ...Er^3＋/Yb^3＋ co-doped SrY2O4 phosphors with high color purity and brightness were successfully synthesized via a solid-state reaction method.Luminescence spectrum studies showed that the main red peaks and the minor green peaks of upconversion emissions were located at approximately 634–681 nm and 543–570 nm,respectively,corresponding to the transitions of ~4F（9/2）→~4I（15/2） and ~4S（3/2）→~4I（15/2） of Er^3＋ ions.Under the excitation of 980 and 1550 nm lasers,the spectra of all of the samples exhibited similar peak positions but different intensities.When excited by the 980 nm laser,the intensity ratio of red to green emission increased with increasing Yb^3＋ doping concentration and decreased with increasing excitation power.In the case of 1550 nm excitation,the intensity ratio of red to green emission increased with increasing Yb^3＋ doping concentration and excitation power,thereby,improving the color purity of the red emission.The intensity of red emission was considerably stronger under 1550 nm excitation than that under 980 nm excitation.Therefore,the color of the proposed phosphors could be efficiently tuned by tailoring both the Yb^3＋ doping concentration and excitation power.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant No. 10804015 )the Science Foundation of the Education Department of Liaoning Province of China (Grant No. 2009A417)
文摘yb^3＋：Er^3＋ co-doped oxy-fluoride ceramics glass has been prepared. The mechanism of up-conversion emissions about Er^3＋ was discussed, and the temperature properties of green up-conversion fluorescence between 303 and 823 K were investigated. The results show that the sensitivity of this sample reaches its maximum value, about 0.0047 K^-1, when the temperature is 383 K, indicating that this kind of sample can be used as high temperature and high sensitivity optical temperature sensor.
文摘Er^3 ＋/Yb^3 ＋ phosphate glasses were fabricated. According to McCumber theory, the stimulated emission cross-section of Er^3＋ ions at 1533 nm was calculated on the basis of absorption spectrum, and 0.84 × 10^-20 cm^2 is derived, the fluorescence lifetime of ^4I13/2 level is 8.5 ms. An Er^3＋/Yb^3＋ co-doped phosphate glass CW laser pumped by LD was demonstrated at room temperature. The maximum output power is 80 mW and slope efficiency is 16.5%.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61265004,51272097,and 11204113)the Nature and Science Fund from Yunnan Province Ministry of Education,China(Grant No.2011C13211708)
文摘The Er^3＋/yb^3＋ co-doped transparent oxyfluoride glass-ceramics containing CaF2 nano-crystals were successfully prepared. After heat treatments, transmission electron microscopy （TEM） images showed that CaF2 nano-crystals of 20-30 nm in diameter precipitated uniformly in the glass matrix. luminescence of Er^3＋ at 540 nm and 658 nm was observed in Comparing with the host glass, high efficiency upconversion the glass ceramics under the excitation of 980 nm. Moreover, the size of the precipitated nano-crystals can be controlled by heat-treatment temperature and time. With the increase of the nano-crystal size, the intensity of the red emission increased more rapidly than that of the green emission. The energy transfer process of Er^3＋ and Yb^3＋ was convinced and the possible mechanism of Er^3＋ up-conversion was discussed.
基金the National Defense Foundation Research Item of China(No.K 1203061109)
文摘The photoluminescence （PL） characteristics of Eu^3＋ and Li^＋ co-doped ZnO PL materials against heat-treatment temperature were discussed. The PL xerogel and powder samples were prepared by solgel process. The emission spectra of all samples showed two broad bands peaking at 590 nm and 620 nm under UV-Vis excitation. But the relative intensity of red PL （620 nm） was much greater than that of green PL （590 nm） of the same sample, that s to say, the red color was the main luminescence. With heat-treatment temperature increase, the two kinds of colors PL intensity decreased, and both the red and green PL intensity of the xerogel samples was much greater than those of powder samples respectively. The XRD patterns revealed that Eu^3＋ ions were successfully incorporated in ZnO crystals in xerogel samples. When heat-treatment temperature reached 350 ℃, the Eu^3＋ began to separate out of the ZnO crystals and Eu2O3 crystals came into being. When the powder sample was subjected to UV-Vis excitation, the energy transfered from the host ZnO emission to Eu^3＋ became weaker than the xerogel sample.
文摘Er3+-Yb3+ co-doped fiber of 2 m long is used as the laser gain medium. Two fiber lasers with different structures have been set up, one is the line cavity fiber laser with the dielectric mirror being replaced by an all-fiber reflecting mirror,the other is the ring cavity all-fiber laser. Both set-ups have achieved lasing operation at the wavelength of 1.53 μm. Pumped by the 1 064 nm light from all-solid-state Nd ∶YAG laser, the two fiber lasers at 1 530 nm are operational. Their output powers are 7.8 mW and 2 mW with 130 mW and 160 mW pump powers.
基金Project supported by the National Natural Science Foundation of China (Grant No. 10804015)the Science Foundation of the Education Department of Liaoning Province of China (Grant No. 2009A417)
文摘Yb^3＋：Er^3＋：Tm^3＋co-doped borosilicate glasses are prepared. Their strong up-conversion photoluminescence spectra in a range from ultra-violet to near-infrared, which are excited by a 978-nm laser diode, are measured, and the mechanisms of energy transfer among Yb^3＋ Er^3＋ and Tm^3＋ ions are discussed. The results show that there is an unexpected wavelength at 900-nm emission from Yb^3＋ Stark splitting levels to pump Tm^3＋ ions and there exists an optimum pump power. The concentration of the Tm^3＋ dopant gives rise to a prominent effect on the intensity of visible and near-infrared emissions for the yb^3＋：Er^3＋：Tm^3＋ co-doped borosilicate glasses.
文摘An all-fiber based Er~ 3+ ∶Yb~ 3+ co-doped double clad fiber laser operating at 1550nm is demonstrated. By using 9m long Er~ 3+ ∶Yb~ 3+ co-doped fiber(EYDF) as the gain medium, and using a pair of fiber Bragg gratings as wavelength filters, the line-width of the output laser is as narrow as 0.2nm and the output power is more than 6mW. The fluorescent effect of the laser before its emission is also studied. And it is found that the Er~ 3+ ∶Yb~ 3+ co-doped double-clad fiber laser also exhibits a high gain for Yb~ 3+ transition near 1080nm.
文摘Based on propagation-rate equations, the influence of different input pulse durations on the properties of Er^3＋/Yb^3＋ co-doped double-clad fiber amplifier at dynamic equilibrium was analyzed. The change characteristic of output power sag with pulse duration and repetition rate was shown. Whether single or multichannel input pulses are amplified, the shorter the input pulse duration is, the smaller the power sags of output pulse will be. At low repetition rate, upper gain values（Gupper） of gain swing are almost the same for different input pulse durations, which tend to the small signal gain, but lower gain value（Glower） of short input pulse is larger than that of long input pulse. At highrepetition rate, lower gain value（Glower） approaches to upper gain value（Glower）.
基金Project supported by Scientific Research Fund of Zhejiang Provincial Education Department (20061660)Foundation ofNingbo University (xk200435)
文摘The growth of LiNbO3 single crystal with Er^3＋ and Zn^2＋ co-doped using Bridgman method and its characteristic absorption spectra and fluorescence spectra were reported. Large-size crystals initially containing Zn^2＋ （3%） and Er^3＋ （0.6%） with good optical quality were obtained using optimized conditions such as a growth rate of 0.8- 1.5 mm·h^-1 and a temperature gradient of about 30 - 35℃·cm^-1 across the solid-liquid interface and the sealed platinum crucible. X-ray diffraction and differential thermal analysis （DTA） were used to characterize the crystals. The results indicate that the concentration of Er^3＋ ions in crystals, their absorption intensity, and their fluorescence intensity decrease from the bottom to the top in the crystals. However, for the upper part of the crystal, the up-conversion fluorescence intensity is higher than that of the lower part excited by an 800 or 970 nm pump. The effects of the crystal lattice, their structural defect and their effective segregation of Er^3＋ ions were discussed with respect to the variations of the up-conversion fluorescence intensity.
文摘The growth of LiNbO3 single crystal with Er^3＋/Zn^2＋ co-doped by the bridgman method and the characteristics of absorption spectra and fluorescence spectra were reported. By means of the optimized con- ditions such as growth rate of 0.8 - 1.5 mm · h^- 1, temperature gradient about 30 - 35℃ ·cm^-1 across the solid-liquid interface and sealed platinum, large size crystals containing Zn^2＋ （3%） and Er^3＋ （0.6%） with good optical quality were obtained. X-ray diffraction and DTA were used to characterize the crystals. The results indicate that the concentration of Er^3＋ ions in crystals decrease along the growth direction, the absorption intensity and the fluorescence intensity ions also decrease along the growth direction. of Er^3＋ However, for the upper part crystal, the upconversion fluorescence intensity is higher than that of the lower part crystal excited with 800 or 970 nm pump. The effects of crystal lattice, structure defect and effective segregation of Er^3＋ ions were discussed in respect to the variations were discussed of upconversion fluorescence intensity.
文摘The Er3＋/yb3＋ co-doped phosphate （EYDP） glass waveguides operated at 1539 nm have been manufactured by using the implantation technique of carbon ions under the condition of 6.0 MeV energy and 5.0 × 10^13 ions/cm2 fluence in this work. The ion implantation process was computed by means of the stopping and range of ions in matter. The dark-mode spectrum at 1539 nm of the waveguide was recorded by the method of the prism coupling measurement. The microscopic image of the fabricated structure was photographed by an optical microscope. It is the first step for the application of the waveguides on the base of EYDP glasses in optical- integrated photonic devices at near-infrared band.
基金Project supported by the China National Funds for Distinguished Young Scientists(61325024)Hi-tech Research and Development Program of China(National 863 Project:2014AA041902)+2 种基金National Nature Science Foundation of China(11174085,51132004,51302086)the Fund of Guangdong Province Cooperation of Producing,Studying and Researching(2012B091100140)Guangdong Natural Science Foundation(S2011030001349)
文摘A detailed study of the fluorescence emission properties and energy transfer mechanism in Er^（3＋）/Tm^（3＋） co-doped lead silicate glasses was reported. Enhanced near infrared 1.8 μm and visible up-conversion emissions were investigated under 808 and 980 nm excitations, respectively. The energy transfer mechanism between Er^（3＋） and Tm^（3＋） was analyzed according to the absorption spectra, the emission spectra and the level structures of Er^（3＋） and Tm^（3＋）. The energy transfer efficiency between Er^（3＋） and Tm^（3＋） reached 68.1% in the Er^（3＋）/Tm^（3＋） co-doped lead silicate glasses when pumped by 808 nm laser diode. Based on the absorption spectra, the Judd-Ofelt parameters, spontaneous emission probability, absorption and emission cross sections, gain coefficients were calculated and analyzed. It was found that the calculated emission cross section and the maximum gain coefficient around 1.8 μm were 4.9×10^（–21）cm^2 and 1.12 cm^（–1）, respectively. These results indicated that the Er^（3＋）/Tm^（3＋） co-doped lead-silicate glasses had potential application in near infrared lasers.
基金Project supported by the National Natural Science Foundation of China(No.61465006)the Reserve talents project of Yunnan Province(2015HB013)
文摘BiOCl crystal shows potential as efficient optical host due to its special layered structure. Here,the luminescence properties of the Er^3＋/Sm^3＋ co-doped BiOCl phosphors as single-phase phosphors were reported. Upon near ultraviolet excitation（NUV, 380 nm corresponding the ^4 I15/2→ ^4 G11/2 transition of Er^3＋ ions）, the phosphors exhibit the efficient characteristic emissions of Er^3＋ and Sm^3＋ ions simultaneously. The energy transfer（ET） from Er^3＋ to Sm^3＋ ions in the layered crystals has been validated by the variation of emission intensities and decay lifetimes respectively, which is ascribed to be a dipoledipole interaction. By virtue of the ET behavior and increasing Sm^3＋ ion concentration, the enhancing emission intensity of Sm^3＋ and the tunability of emission color from yellowish-green（0.318, 0.420） to white（0.343, 0.347） are realized. The results of our work indicate that the Er^3＋/Sm^3＋ co-doped BiOCI phosphor has a promising application serving as single component white emitting phosphors for NUV excited WLEDs.
基金Project supported by Research Program of Application Foundation(Main subject)of Ministry of Transport of China(2015329225090)Fundamental Research Funds for the Central Universities(3132014327,3132015150,3132015153,3132015139)+2 种基金Program for Liaoning Excellent Talents in University(LR2013020)Foundation of Liaoning Educational Committee(L2013201,L2014212,L2014208)the National Natural Science Foundation of China(11504039,51502031)
文摘Er^3＋/Yb^3＋ co-doped SrY2O4 phosphors with high color purity and brightness were successfully synthesized via a solid-state reaction method.Luminescence spectrum studies showed that the main red peaks and the minor green peaks of upconversion emissions were located at approximately 634–681 nm and 543–570 nm,respectively,corresponding to the transitions of ~4F（9/2）→~4I（15/2） and ~4S（3/2）→~4I（15/2） of Er^3＋ ions.Under the excitation of 980 and 1550 nm lasers,the spectra of all of the samples exhibited similar peak positions but different intensities.When excited by the 980 nm laser,the intensity ratio of red to green emission increased with increasing Yb^3＋ doping concentration and decreased with increasing excitation power.In the case of 1550 nm excitation,the intensity ratio of red to green emission increased with increasing Yb^3＋ doping concentration and excitation power,thereby,improving the color purity of the red emission.The intensity of red emission was considerably stronger under 1550 nm excitation than that under 980 nm excitation.Therefore,the color of the proposed phosphors could be efficiently tuned by tailoring both the Yb^3＋ doping concentration and excitation power.
