Crystal field splitting of 4fn−15d-levels of Ce3+ and Eu2+ in nitride compounds

Wang, Shuxin; Song, Zhen; Kong, Yuwei; Xia, Zhiguo; Liu, Quanlin

doi:10.1016/j.jlumin.2017.10.073

Cited by 90 publications

(45 citation statements)

References 68 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We here pay attention to oxide/oxyfluoride hosts and summarize the available structures/sites in which Ce 3+ can be efficiently excited by a relatively low energy photon (listed in Table ). As seen, a large ε cfs was mainly obtained when Ce 3+ was accommodated in these sites with six or eightfold coordination (which are relatively small coordination numbers) . Among them, the garnet‐type ones have been the dominant commercial green‐to‐yellow phosphors for a long time due to the high quantum efficiency and high thermal quenching temperature .…”

Section: Introductionmentioning

confidence: 95%

Local coordination, electronic structure, and thermal quenching of Ce³⁺ in isostructural Sr₂GdAlO₅ and Sr₃AlO₄F phosphors

Asami

et al. 2018

J Am Ceram Soc

View full text Add to dashboard Cite

Sr2GdAlO5:Ce and Sr3AlO4F:Ce are isostructural phosphors in which the Ce3+ 4f‐5d1 transition can be efficiently excited by a photon with energy lower than 3.1 eV. Herein, we analyze the crystal chemistry of the Ce3+ local coordination, compare the thermal quenching behavior and construct the electronic structure of Ce3+ in them. The Rietveld refinement on two occupancy models suggests that Gd3+ only occupies the 8h site in Sr2GdAlO5; this provides a hint on the preferred occupancy of dopant Ce3+ in this site. The large crystal filed splitting of Ce8h is mainly due to the fact that the 8h site is bonded to two oxygen with relatively short dSr/Gd‐O and forms a quasi‐square antiprism which experiences a large distortion. The Ce3+ 5d‐4f luminescence in Sr3AlO4F is much more stable against thermal quenching than that in Sr2GdAlO5, as evidenced by the temperature‐dependent luminescence intensity and luminescence decay studies. The energy of the O2−‐Eu3+/2+ and O2−‐Ce4+/3+ charge transfer as well as bandgap were estimated and the electronic structure of Ce3+ were constructed. A larger energy barrier ΔEdC between the Ce3+ 5d1 level and the conduction band bottom in Sr3AlO4F is seen from the Vacuum Referred Binding Energy (VRBE) diagrams which explains the higher thermal quenching temperature by thermal ionization model.

show abstract

Section: Introductionmentioning

confidence: 95%

Local coordination, electronic structure, and thermal quenching of Ce³⁺ in isostructural Sr₂GdAlO₅ and Sr₃AlO₄F phosphors

Asami

et al. 2018

J Am Ceram Soc

View full text Add to dashboard Cite

show abstract

“…Compared to that of the red-emitting Sr[LiAl 3 N 4 ]:Eu 2+ phosphor, the emission peak of NKLSO:Eu 2+ has a significant blueshift. Because the formation energy of N 3- from atomic N ( + 2300 kJ mol −1 ) is higher than that of O 2− from atomic O ( + 700 kJ mol −1 ), the bonding in nitrides is notably more covalent than that in oxides 25 . Therefore, the 5 d energy levels of Eu 2+ in nitride would be lower compared to that in oxide, which results in the lower 5 d −4 f transition energy of the Sr[LiAl 3 N 4 ]:Eu 2+ nitride phosphor than that of the NKLSO:Eu 2+ oxide phosphor.…”

Section: Introductionmentioning

confidence: 97%

Emerging ultra-narrow-band cyan-emitting phosphor for white LEDs with enhanced color rendition

et al. 2019

Self Cite

View full text Add to dashboard Cite

Phosphor-converted white LEDs rely on combining a blue-emitting InGaN chip with yellow and red-emitting luminescent materials. The discovery of cyan-emitting (470–500 nm) phosphors is a challenge to compensate for the spectral gap and produce full-spectrum white light. Na 0.5 K 0.5 Li 3 SiO 4 :Eu 2+ (NKLSO:Eu 2+ ) phosphor was developed with impressive properties, providing cyan emission at 486 nm with a narrow full width at half maximum (FWHM) of only 20.7 nm, and good thermal stability with an integrated emission loss of only 7% at 150 °C. The ultra-narrow-band cyan emission results from the high-symmetry cation sites, leading to almost ideal cubic coordination for UCr 4 C 4 -type compounds. NKLSO:Eu 2+ phosphor allows the valley between the blue and yellow emission peaks in the white LED device to be filled, and the color-rendering index can be enhanced from 86 to 95.2, suggesting great applications in full-spectrum white LEDs.

show abstract

“…Compared with (Ca,Sr) 2 Si 5 N 8 matrixes, the reduced coordination number should be another factor for the strong crystal field. Furthermore, polyhedron shape is also related to the crystal field strength 30,39,40 …”

Section: Resultsmentioning

confidence: 99%

Broadband deep‐red‐to‐near‐infrared emission from Mn²⁺ in strong crystal‐field of nitride MgAlSiN₃

et al. 2020

Self Cite

View full text Add to dashboard Cite

Near-infrared (NIR) light source has received increasing attention for application in night-vision imaging, medical fields, the food processing industry, etc. 1-5 Especially, spectral region at 700-1100 nm shows excellent tissue penetration, which enables it advantageous for imaging blood vein distribution in vivo. 6,7 There is great commercial demand for optical devices and consumer electronics equipped with small-size, high efficiency and broadband emission NIR light source. The traditional NIR tungsten-halogen lamps suffer from poor efficiency, large size, short lifetimes and severe heat effect. 8 In contrast, NIR phosphor-converted light-emitting diodes (pc-LEDs) have attracted increasing interests considering the high luminescence efficiency, compact size, availability of simpler strategies for both material design and fabrication. 9-11 Since NIR pc-LEDs fabricated by sharp-line emission phosphors also fail to meet the requirement of commercial promotion due to narrow full width at half maximum (FWHM), 12 it is urgent to exploit NIR phosphors for designing novel solid-state NIR light source. Currently, numerous researchers have focused on Cr 3+ doping inorganic matrices, such as ScBO

show abstract

Crystal field splitting of 4fn−15d-levels of Ce3+ and Eu2+ in nitride compounds

Cited by 90 publications

References 68 publications

Local coordination, electronic structure, and thermal quenching of Ce³⁺ in isostructural Sr₂GdAlO₅ and Sr₃AlO₄F phosphors

Local coordination, electronic structure, and thermal quenching of Ce³⁺ in isostructural Sr₂GdAlO₅ and Sr₃AlO₄F phosphors

Emerging ultra-narrow-band cyan-emitting phosphor for white LEDs with enhanced color rendition

Broadband deep‐red‐to‐near‐infrared emission from Mn²⁺ in strong crystal‐field of nitride MgAlSiN₃

Contact Info

Product

Resources

About

Crystal field splitting of 4fn−15d-levels of Ce3+ and Eu2+ in nitride compounds

Cited by 90 publications

References 68 publications

Local coordination, electronic structure, and thermal quenching of Ce3+ in isostructural Sr2GdAlO5 and Sr3AlO4F phosphors

Local coordination, electronic structure, and thermal quenching of Ce3+ in isostructural Sr2GdAlO5 and Sr3AlO4F phosphors

Emerging ultra-narrow-band cyan-emitting phosphor for white LEDs with enhanced color rendition

Broadband deep‐red‐to‐near‐infrared emission from Mn2+ in strong crystal‐field of nitride MgAlSiN3

Contact Info

Product

Resources

About

Local coordination, electronic structure, and thermal quenching of Ce³⁺ in isostructural Sr₂GdAlO₅ and Sr₃AlO₄F phosphors

Local coordination, electronic structure, and thermal quenching of Ce³⁺ in isostructural Sr₂GdAlO₅ and Sr₃AlO₄F phosphors

Broadband deep‐red‐to‐near‐infrared emission from Mn²⁺ in strong crystal‐field of nitride MgAlSiN₃