In the present study,a simple method for the preparation of a luminescent flexible gallium doped zinc oxide(GZO)/polystyrene nanocomposite film was developed.The prepared GZO powder was characterized through different...In the present study,a simple method for the preparation of a luminescent flexible gallium doped zinc oxide(GZO)/polystyrene nanocomposite film was developed.The prepared GZO powder was characterized through different optical and structural techniques.The XRD study revealed the existence of a wurtzite structure with no extra oxide peaks.Elemental-mapping,EDX,FTIR and XPS analyses were used to confirm the presence of elements and the several groups present in the structure.Under excitations of UV,the prepared hybrid nanocomposite showed a strong cyan emission with narrow full width at half the maximum value(20 nm)that has not been reported before.X-ray and laser-induced luminescence results of the hy-brid film revealed novel blue-green emission at room temperature.The prepared composite film showed a strong scintillation re-sponse to ionizing radiation.The strong emissions,very weak deep-level emissions,and low FWHM of composite indicate the de-sirable optical properties with low-density structural defects in the GZO composite structure.Therefore,the prepared hybrid film can be considered to be a suitable candidate for the fabrication of optoelectronic devices.展开更多
Self-reducing phosphors have attracted significant attention due to their avoidance of hazardous gases(H_(2)/CO/N_(2)),offering safer and more economical alternatives.This work reveals oxygen vacancy defect-induced Ce...Self-reducing phosphors have attracted significant attention due to their avoidance of hazardous gases(H_(2)/CO/N_(2)),offering safer and more economical alternatives.This work reveals oxygen vacancy defect-induced Ce3+self-reduction behavior in garnet structure.The Ca_(2)Gd_(1-x)Zr_(2)Al_(3)O_(12):Ce^(3+)cyan phosphors were successfully synthesized via conventional high-temperature solidstate reaction in ambient atmosphere.Photoluminescence(PL) spectra revealed a strong emission centered at 490 nm,aligning well with the cyan component required in WLEDs.The relatively short fluorescence lifetime further implies the potential of CGZA:Ce^(3+/4+)phosphors for high-speed visible light communication(VLC).By combining electron paramagnetic resonance(EPR) spectroscopy with density functional theory(DFT) calculations,the self-reduction behavior of Ce^(4+)to Ce^(3+)in the garnet structure was elucidated.The results suggest that oxygen vacancies play a critical role in facilitating the reduction process.DFT calculations revealed that Ce doping significantly lowers the formation energy of oxygen vacancies,thereby promoting self-reduction.These findings provide valuable insights into the design of novel self-reducing Ce^(3+)-based phosphors for advanced lighting and optical communication applications.展开更多
There are many strategies to maintain the excellent photoluminescence(PL) characteristics of perovskite quantum dots(QDs). Here, we proposed a facile and effective method to prepare cyan CsPb(Cl/Br)3/SiO2 nanospheres ...There are many strategies to maintain the excellent photoluminescence(PL) characteristics of perovskite quantum dots(QDs). Here, we proposed a facile and effective method to prepare cyan CsPb(Cl/Br)3/SiO2 nanospheres at room temperature. Cubic CsPb(Cl/Br)3 was obtained by adding a LiCl-H2O solution and anion exchange reaction. With(3-aminopropyl)triethoxysilane as an auxiliary agent, a QDs/SiO2 composite was extracted from a sol-gel solution by precipitate-encapsulation method. The transmission electron microscopy images and Fourier transform infrared spectra indicated the QDs were indeed embedded in silica substances.Besides, humidity stability and thermal stability show the composite possesses a great application value.Finally, cyan QDs@SiO2 powder has a high PL quantum yield of up to 84%;the stable cyan fluorescent powder does have great potential to play a key role in commercial full spectrum display.展开更多
In order to realize full-spectrum lighting,excellent blue-cyan phosphors,which can be excited by violet LED chips,are particularly important to compensate for the spectral cyan gap.Herein,we report an efficient and th...In order to realize full-spectrum lighting,excellent blue-cyan phosphors,which can be excited by violet LED chips,are particularly important to compensate for the spectral cyan gap.Herein,we report an efficient and thermally stable Eu^(2+)-doped T-phase blue-cyan phosphor,Ba_(1.3)0_(5)Ca_(0.38)Mg_(0.3)SiO_(4):0.015Eu^(2+)(BCM_(0.3)S:Eu^(2+))through structure design and composition optimization.The emission spectrum presents an asymmetric band peaking at 475 nm with a small Stokes shift under 400 nm excitation.The internal/external quantum efficiencies of this phosphor are up to 82.9%/66.2%,and the integrated emission intensity at 150℃ is maintained at 90% of that at room temperature.Due to the compensation of the blue-cyan gap,the fabricated white lightemitting diode(pc-WLED),made of BCM0.3S:Eu^(2+)combined with the 400 nm chip and other phosphors,shows an ultra-high color rendering index(R_(a)=95.7).These prominent properties give BCM_(0.3)S:Eu^(2+)potential applications in the field of full-spectrum healthy lighting.展开更多
The currently available commercial white light-emitting diodes(WLEDs)suffer from a poor spectral continuity due to the absence of cyan light.Satisfactory bright cyan phosphors are urgently needed to promote the perfor...The currently available commercial white light-emitting diodes(WLEDs)suffer from a poor spectral continuity due to the absence of cyan light.Satisfactory bright cyan phosphors are urgently needed to promote the performance of WLEDs.Herein,we report a bright cyan-emitting phosphor Ba_(6)BO_(3)Cl_(9):Eu^(2+).The internal quantum efficiency and external quantum efficiency of the Ba_(6)BO_(3)Cl_(9):Eu^(2+)phosphor were measured to be 86.2%and 41.3%,respectively.Also,this phosphor exhibits strong endurance to luminescence thermal quenching,with the luminescence intensity at 150℃retaining 93.9%of the value at room temperature.When applied in full-spectrum phosphor-converted WLEDs,the Ba_(6)BO_(3)Cl_(9):Eu^(2+)phosphor may efficiently compensate for the lack of cyan light emission of WLED devices prepared using blue/yellow/red phosphor strategies and also contribute to the improvement of Ra(color rendering index)of WLED devices based on RGB(red/green/blue)phosphor strategies.In addition,the Ba_(6)BO_(3)Cl_(9):Eu^(2+)phosphor can be applied as an independent efficient blue-cyan component to replace the blue light component in common WLEDs and reduces the proportion of high-energy blue light that is harmful to vision protection.These results demonstrate that Ba_(6)BO_(3)Cl_(9):Eu^(2+)will have a wide range of potential applications in indoor healthy lighting as a cyan phosphor.展开更多
Indigo naturalis(青黛)is also called“indigo flower,”“bright cyan,”and“cyan clam powder.”The alias“indigo flower”shows its complex progress about producing dyes.The alias“bright cyan”vividly displays the visu...Indigo naturalis(青黛)is also called“indigo flower,”“bright cyan,”and“cyan clam powder.”The alias“indigo flower”shows its complex progress about producing dyes.The alias“bright cyan”vividly displays the visual characteristics of indigo naturalis.Its another alias“cyan clam powder”implies its properties,flavors,and particular morphologic characteristics.The name of“indigo naturalis”emphasizes its wide use in ancient times to paint their eyebrows.Indigo naturalis,which comes from the Persian Kingdom,wins the favor and praise of customers in the respects of dye and cosmetics in both Eastern and Western Regions.It not only shows the infinite charm of dye culture in the Western Regions and provides a visual sensation for people,but also adds new color for Chinese medicine culture.展开更多
基金the Iranian National Elites Foundation for the financial support of this research
文摘In the present study,a simple method for the preparation of a luminescent flexible gallium doped zinc oxide(GZO)/polystyrene nanocomposite film was developed.The prepared GZO powder was characterized through different optical and structural techniques.The XRD study revealed the existence of a wurtzite structure with no extra oxide peaks.Elemental-mapping,EDX,FTIR and XPS analyses were used to confirm the presence of elements and the several groups present in the structure.Under excitations of UV,the prepared hybrid nanocomposite showed a strong cyan emission with narrow full width at half the maximum value(20 nm)that has not been reported before.X-ray and laser-induced luminescence results of the hy-brid film revealed novel blue-green emission at room temperature.The prepared composite film showed a strong scintillation re-sponse to ionizing radiation.The strong emissions,very weak deep-level emissions,and low FWHM of composite indicate the de-sirable optical properties with low-density structural defects in the GZO composite structure.Therefore,the prepared hybrid film can be considered to be a suitable candidate for the fabrication of optoelectronic devices.
基金financially supported by the National Natural Science Foundation of China(No.U22A2008)
文摘Self-reducing phosphors have attracted significant attention due to their avoidance of hazardous gases(H_(2)/CO/N_(2)),offering safer and more economical alternatives.This work reveals oxygen vacancy defect-induced Ce3+self-reduction behavior in garnet structure.The Ca_(2)Gd_(1-x)Zr_(2)Al_(3)O_(12):Ce^(3+)cyan phosphors were successfully synthesized via conventional high-temperature solidstate reaction in ambient atmosphere.Photoluminescence(PL) spectra revealed a strong emission centered at 490 nm,aligning well with the cyan component required in WLEDs.The relatively short fluorescence lifetime further implies the potential of CGZA:Ce^(3+/4+)phosphors for high-speed visible light communication(VLC).By combining electron paramagnetic resonance(EPR) spectroscopy with density functional theory(DFT) calculations,the self-reduction behavior of Ce^(4+)to Ce^(3+)in the garnet structure was elucidated.The results suggest that oxygen vacancies play a critical role in facilitating the reduction process.DFT calculations revealed that Ce doping significantly lowers the formation energy of oxygen vacancies,thereby promoting self-reduction.These findings provide valuable insights into the design of novel self-reducing Ce^(3+)-based phosphors for advanced lighting and optical communication applications.
基金supported by the Science and Technology Planning Project of Zhejiang Province(No.2018C01046)Enterprise-Funded Latitudinal Research Projects of China(Nos.J2016-141,J2017-171,J2017-293,and J2017-243)+1 种基金Shanghai Sailing Program(No.18YF1422500)Research Start-Up Project of Shanghai Institute of Technology(No.YJ2018-9)
文摘There are many strategies to maintain the excellent photoluminescence(PL) characteristics of perovskite quantum dots(QDs). Here, we proposed a facile and effective method to prepare cyan CsPb(Cl/Br)3/SiO2 nanospheres at room temperature. Cubic CsPb(Cl/Br)3 was obtained by adding a LiCl-H2O solution and anion exchange reaction. With(3-aminopropyl)triethoxysilane as an auxiliary agent, a QDs/SiO2 composite was extracted from a sol-gel solution by precipitate-encapsulation method. The transmission electron microscopy images and Fourier transform infrared spectra indicated the QDs were indeed embedded in silica substances.Besides, humidity stability and thermal stability show the composite possesses a great application value.Finally, cyan QDs@SiO2 powder has a high PL quantum yield of up to 84%;the stable cyan fluorescent powder does have great potential to play a key role in commercial full spectrum display.
基金supported by the National Natural Science Foundation of China(No.51832005 and No.51972020).
文摘In order to realize full-spectrum lighting,excellent blue-cyan phosphors,which can be excited by violet LED chips,are particularly important to compensate for the spectral cyan gap.Herein,we report an efficient and thermally stable Eu^(2+)-doped T-phase blue-cyan phosphor,Ba_(1.3)0_(5)Ca_(0.38)Mg_(0.3)SiO_(4):0.015Eu^(2+)(BCM_(0.3)S:Eu^(2+))through structure design and composition optimization.The emission spectrum presents an asymmetric band peaking at 475 nm with a small Stokes shift under 400 nm excitation.The internal/external quantum efficiencies of this phosphor are up to 82.9%/66.2%,and the integrated emission intensity at 150℃ is maintained at 90% of that at room temperature.Due to the compensation of the blue-cyan gap,the fabricated white lightemitting diode(pc-WLED),made of BCM0.3S:Eu^(2+)combined with the 400 nm chip and other phosphors,shows an ultra-high color rendering index(R_(a)=95.7).These prominent properties give BCM_(0.3)S:Eu^(2+)potential applications in the field of full-spectrum healthy lighting.
基金supported by the National Key R&D program of China(Grant No.2019YFA0709101)the National Natural Science Foundation of China(Grant No.52072364)+1 种基金R&D Projects in Key Areas of Guangdong Province(Grant No.2020B0101010001)the Key Research Program of the Chinese Academy of Sciences,(Grant No.ZDRW-CN-2021-3-3-06).
文摘The currently available commercial white light-emitting diodes(WLEDs)suffer from a poor spectral continuity due to the absence of cyan light.Satisfactory bright cyan phosphors are urgently needed to promote the performance of WLEDs.Herein,we report a bright cyan-emitting phosphor Ba_(6)BO_(3)Cl_(9):Eu^(2+).The internal quantum efficiency and external quantum efficiency of the Ba_(6)BO_(3)Cl_(9):Eu^(2+)phosphor were measured to be 86.2%and 41.3%,respectively.Also,this phosphor exhibits strong endurance to luminescence thermal quenching,with the luminescence intensity at 150℃retaining 93.9%of the value at room temperature.When applied in full-spectrum phosphor-converted WLEDs,the Ba_(6)BO_(3)Cl_(9):Eu^(2+)phosphor may efficiently compensate for the lack of cyan light emission of WLED devices prepared using blue/yellow/red phosphor strategies and also contribute to the improvement of Ra(color rendering index)of WLED devices based on RGB(red/green/blue)phosphor strategies.In addition,the Ba_(6)BO_(3)Cl_(9):Eu^(2+)phosphor can be applied as an independent efficient blue-cyan component to replace the blue light component in common WLEDs and reduces the proportion of high-energy blue light that is harmful to vision protection.These results demonstrate that Ba_(6)BO_(3)Cl_(9):Eu^(2+)will have a wide range of potential applications in indoor healthy lighting as a cyan phosphor.
文摘Indigo naturalis(青黛)is also called“indigo flower,”“bright cyan,”and“cyan clam powder.”The alias“indigo flower”shows its complex progress about producing dyes.The alias“bright cyan”vividly displays the visual characteristics of indigo naturalis.Its another alias“cyan clam powder”implies its properties,flavors,and particular morphologic characteristics.The name of“indigo naturalis”emphasizes its wide use in ancient times to paint their eyebrows.Indigo naturalis,which comes from the Persian Kingdom,wins the favor and praise of customers in the respects of dye and cosmetics in both Eastern and Western Regions.It not only shows the infinite charm of dye culture in the Western Regions and provides a visual sensation for people,but also adds new color for Chinese medicine culture.
