4f and 5d energy levels of the divalent and trivalent lanthanide ions in M2Si5N8 (M=Ca, Sr, Ba)

Kate, ten Om Melvin; Zhang, Z Zhijun; Dorenbos, P.; Hintzen, Htjm Bert; Kolk, van der E

doi:10.1016/j.jssc.2012.08.029

Cited by 64 publications

(34 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The charge transfer energy of a trivalent lanthanide should correspond to the energy needed to bring an electron from the top of the valence band to the 4f ground state of the divalent ion. 14,15 The aforementioned CT band of Sm 3þ in CaZnOS observed around 3.3 eV determines the position of the divalent Sm 4f ground state with respect to the top of the valence band (arrow 3) in Fig. 11.…”

Section: G Construction and Discussion Of The Energy Level Diagram Omentioning

confidence: 99%

Photoluminescence properties and energy levels of RE (RE = Pr, Sm, Er, Tm) in layered-CaZnOS oxysulfide

Zhang

Feng

Chen

et al. 2013

Journal of Applied Physics

View full text Add to dashboard Cite

Vacuum ultraviolet spectroscopic properties of rare earth ( RE = Ce , Tb , Eu , Tm , Sm ) -doped hexagonal K Ca Gd ( P O 4 ) 2 phosphate RE 3þ (RE ¼ Pr, Sm, Er, Tm)-activated CaZnOS samples were prepared by a solid-state reaction method at high temperature, and their photoluminescence properties were investigated. Doping with RE 3þ (RE ¼ Pr, Sm, Er, Tm) into layered-CaZnOS resulted in typical RE 3þ (RE ¼ Pr, Sm, Er, Tm) f-f line absorptions and emissions, as well as the charge transfer band of Sm 3þ at about 3.3 eV. The energy level scheme containing the position of the 4f and 5d levels of all divalent and trivalent lanthanide ions with respect to the valence and conduction bands of CaZnOS has been constructed based on the new data presented in this work, together with the data from literature on Ce 3þ and Eu 2þ doping in CaZnOS. The detailed energy level scheme provides a platform for interpreting the optical spectra and could be used to comment on the valence stability of the lanthanide ions in CaZnOS. V C 2013 AIP Publishing LLC. [http://dx.

show abstract

Section: G Construction and Discussion Of The Energy Level Diagram Omentioning

confidence: 99%

Photoluminescence properties and energy levels of RE (RE = Pr, Sm, Er, Tm) in layered-CaZnOS oxysulfide

Zhang

Feng

Chen

et al. 2013

Journal of Applied Physics

View full text Add to dashboard Cite

show abstract

“…[1][2][3][4][5] Phosphors for white LEDs should have good thermal stability and conversion efficiency and an excitation wavelength range in the UV to blue region (370-460 nm). [3,[6][7][8] The yellow-emitting phosphor (Y,Gd) 3 (Al,Ga) 5 O 12 :Ce 3+ is a well-known commercial example, but the lack of red emission results in cold white light and a low color-rendering index (CRI). [1,7,9,10] Nitride-based materials are more covalent than oxides, which improves thermal stability, and their greater crystal field splitting increases the red emission leading to warmer white light.…”

mentioning

confidence: 99%

Nanosegregation and Neighbor‐Cation Control of Photoluminescence in Carbidonitridosilicate Phosphors

et al. 2013

View full text Add to dashboard Cite

Blue, green, and yellow phosphors are obtained in the Sr1−xY0.98+xCe0.02Si4N7−xCx system (x=0→1). Decreases in thermal quenching barrier height with x result from a dominant neighboring‐cation effect, through which the replacement of Sr2+ by Y3+ reduces the covalency of CeN bonding. Green emission is observed from a cation‐segregated nanostructure of SrYSi4N7 and Y2Si4N6C domains in x=0.2–0.6 samples.

show abstract

“…Such compact structures provide strong crystal fields and covalent nature for nitridosilicate phosphors. The above characteristics result in a relatively broad excitation range, long emission wavelengths, and low thermal quenching behavior7891011.…”

mentioning

confidence: 99%

“…However, the high reaction temperatures (1350–1600 °C) exceed the melting point for one of the constituent materials, Sr 3 N 2 (m.p. = 1030 °C)1011121314. Excessive liquid phase during the reaction causes non-homogeneous reactions, resulting in phosphors with low quality and insufficient emission intensity.…”

mentioning

confidence: 99%

Synthesis of Sr2Si5N8:Ce3+ phosphors for white LEDs via efficient chemical vapor deposition

Yang

Som

Das

et al. 2017

Sci Rep

View full text Add to dashboard Cite

Novel chemical vapor deposition (CVD) process was successfully developed for the growth of Sr2Si5N8:Ce3+ phosphors with elevated luminescent properties. Metallic strontium was used as a vapor source for producing Sr3N2 vapor to react with Si3N4 powder via a homogeneous gas-solid reaction. The phosphors prepared via the CVD process showed high crystallinity, homogeneous particle size ranging from 8 to 10 μm, and high luminescence properties. In contrast, the phosphors prepared via the conventional solid-state reaction process exhibited relative low crystallinity, non-uniform particle size in the range of 0.5–5 μm and relatively lower luminescent properties than the phosphors synthesized via the CVD process. Upon the blue light excitation, Sr2−xCexSi5N8 phosphors exhibited a broad yellow band. A red shift of the emission band from 535 to 556 nm was observed with the increment in the doping amount of Ce3+ ions from x = 0.02 to x = 0.10. The maximum emission was observed at x = 0.06, and the external and internal quantum efficiencies were calculated to be 51% and 71%, respectively. Furthermore, the CVD derived optimum Sr1.94Ce0.06Si5N8 phosphor exhibited sufficient thermal stability for blue-LEDs and the activation energy was calculated to be 0.33 eV. The results demonstrate a potential synthesis process for nitride phosphors suitable for light emitting diodes.

show abstract

4f and 5d energy levels of the divalent and trivalent lanthanide ions in M2Si5N8 (M=Ca, Sr, Ba)

Cited by 64 publications

References 36 publications

Photoluminescence properties and energy levels of RE (RE = Pr, Sm, Er, Tm) in layered-CaZnOS oxysulfide

Photoluminescence properties and energy levels of RE (RE = Pr, Sm, Er, Tm) in layered-CaZnOS oxysulfide

Nanosegregation and Neighbor‐Cation Control of Photoluminescence in Carbidonitridosilicate Phosphors

Synthesis of Sr2Si5N8:Ce3+ phosphors for white LEDs via efficient chemical vapor deposition

Contact Info

Product

Resources

About