Electron transfer processes in rare earth doped insulators

Happek, U.; Basun, S. A.; Choi, Jinmu; Krebs, J.K; Raukas, M.

doi:10.1016/s0925-8388(00)00630-7

Cited by 69 publications

(54 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Especially for host lattices, where the SS for the fd emission is small and, yet, the quenching temperature for the luminescence is low, it is clear that thermally induced ionization from the fd state to the conduction band is responsible for temperature quenching of the luminescence. Confirmation has been obtained by temperature dependent photoconductivity experiments [31]. In the present composition the SS is small and the luminescence quenching temperature is relatively high, and there is no clear proof for either of the mechanisms being responsible for the temperature quenching.…”

Section: Article In Presssupporting

confidence: 59%

Luminescence properties of SrSi2O2N2 doped with divalent rare earth ions

Bachmann

Jüstel

Meijerink

et al. 2006

Journal of Luminescence

223

158

View full text Add to dashboard Cite

The optical properties of SrSi 2 O 2 N 2 doped with divalent Eu 2+ and Yb 2+ are investigated. The Eu 2+ doped material shows efficient green emission peaking at around 540 nm that is consistent with 4f 7 -4f 6 5d transitions of Eu 2+ . Due to the high quantum yield (90%) and high quenching temperature (4500 K) of luminescence, SrSi 2 O 2 N 2 :Eu 2+ is a promising material for application in phosphor conversion LEDs. The Yb 2+ luminescence is markedly different from Eu 2+ and is characterized by a larger Stokes shift and a lower quenching temperature. The anomalous luminescence properties are ascribed to impurity trapped exciton emission. Based on temperature and time dependent luminescence measurements, a schematic energy level diagram is derived for both Eu 2+ and Yb 2+ relative to the valence and conduction bands of the oxonitridosilicate host material. r

show abstract

Section: Article In Presssupporting

confidence: 59%

Luminescence properties of SrSi2O2N2 doped with divalent rare earth ions

Bachmann

Jüstel

Meijerink

et al. 2006

Journal of Luminescence

223

158

View full text Add to dashboard Cite

show abstract

“…In some compounds quenching already starts below room temperature which then degrades the room temperature quantum efficiency [2][3][4]. Soon a rule was observed for series of alkaline earth compounds; the quenching temperature T 0.5 , i.e.…”

Section: Introductionmentioning

confidence: 99%

Thermal quenching of Eu²⁺5d–4f luminescence in inorganic compounds

Dorenbos

2005

J. Phys.: Condens. Matter

414

400

View full text Add to dashboard Cite

The thermal quenching of Eu 2+ 5d-4f emission on Ba, Sr, or Ca sites in compounds is often attributed to a large displacement between the ground state and excited state in the configuration coordinate diagram. This work will demonstrate that the ionization of the 5d electron to conduction band states is the genuine quenching mechanism. A model is proposed to explain why in some types of compounds the quenching temperature decreases when going from the Ba variant via the Sr variant to the Ca variant and in other types of compounds the reverse behaviour occurs. The nature of the bottom of the conduction band plays an important role in this.

show abstract

“…Absence of 5d → 4f luminescence of Ce 3+ therefore strongly suggests an alternative nonradiative luminescence quenching route. Photoconductivity studies on Lu 2 4 demonstrated that luminescence quenching proceeds via Ce 3+ ionization and subsequent nonradiative recombination between Ce 4+ and the electron. The preferred nonradiative ionization route was explained by the unfavorable location of the lowest energy 5d state in the conduction band ͑CB͒ of Lu 2 O 3 .…”

Section: Introductionmentioning

confidence: 99%

Luminescence quenching by photoionization and electron transport in a LaAlO3:Ce3+ crystal

Kolk

Haas

Bos

et al. 2007

Journal of Applied Physics

View full text Add to dashboard Cite

A combined photoconductivity, absorption, and thermoluminescence study was performed to understand the absence of luminescence from Ce 3+ in LaAlO 3 :Ce 3+ . It is demonstrated that the absence of luminescence is the result of Ce 3+ ionization from the 5d excited states, which are all located in the conduction band. Ce 3+ ionization is accompanied by the formation of several broad absorption and photoconductivity bands, which are assigned to electron traps. A time and temperature dependent optical investigation of these traps reveals the conditions under which electrons are transferred from Ce 3+ to traps and vice versa, from traps back to Ce 4+ . The observed difference in energy needed to thermally or optically release electrons from traps is qualitatively explained in terms of the location of the ground and excited states of the electron traps with respect to the conduction band.

show abstract

Electron transfer processes in rare earth doped insulators

Cited by 69 publications

References 12 publications

Luminescence properties of SrSi2O2N2 doped with divalent rare earth ions

Luminescence properties of SrSi2O2N2 doped with divalent rare earth ions

Thermal quenching of Eu²⁺5d–4f luminescence in inorganic compounds

Luminescence quenching by photoionization and electron transport in a LaAlO3:Ce3+ crystal

Contact Info

Product

Resources

About

Electron transfer processes in rare earth doped insulators

Cited by 69 publications

References 12 publications

Luminescence properties of SrSi2O2N2 doped with divalent rare earth ions

Luminescence properties of SrSi2O2N2 doped with divalent rare earth ions

Thermal quenching of Eu2+5d–4f luminescence in inorganic compounds

Luminescence quenching by photoionization and electron transport in a LaAlO3:Ce3+ crystal

Contact Info

Product

Resources

About

Thermal quenching of Eu²⁺5d–4f luminescence in inorganic compounds