共查询到20条相似文献,搜索用时 0 毫秒
1.
Growth and the luminescence properties of a lutetium gadolinium garnet doped with Ce3+ and Pr3+ ions
S. V. Nizhankovsky A. Ya. Dan’ko Yu. V. Zorenko V. V. Baranov L. A. Grin’ V. F. Tkachenko P. V. Mateichenko 《Physics of the Solid State》2011,53(1):127-130
Crystals of lutetium gadolinium garnet solid solutions (Lu1 − x
Gd
x
)Al5O12 (0 ≤ x ≤ 0.6) doped with Ce3+ and Pr3+ ions have been prepared by the horizontal directional crystallization method, and their optical and luminescence properties
have been investigated. It has been established that the introduction of gadolinium into the lutetium garnet lattice leads
to a decrease in the antisite luminescence (LuAl centers) in the UV spectral range and to sensitization of the Ce3+ ion luminescence. By contrast, the presence of gadolinium results in the quenching of the Pr3+ luminescence due to the nonradiative excitation transfer from Pr3+ ions to Gd3+ ions. 相似文献
2.
3.
J.L. Sommerdijk J.A.W. van der Does de Bye P.H.J.M. Verberne 《Journal of luminescence》1976,14(2):91-99
Decay measurements have been performed on the Ce3+ luminescence of LaMgAl11O19 : Ce3+ and of CeMgAl11O19 activated with Tb3+. For all samples, the decay was found to be nearly exponential over at least two decades, and the decay time constant was practically the same, being ≈20 ns. From these results and from quantum efficiency data of the Ce3+ luminescence, conclusions are drawn about the various energy transfers and quenching interactions occurring in these compounds. 相似文献
4.
Powder samples of KSrPO4 doped with Eu2+ and Ce3+ were prepared by combustion-assisted synthesis. Their structures and photoluminescence spectra were systemically studied.
Energy transfer from Ce3+ to Eu2+ was observed by investigating the optical properties from photoluminescence spectra in Eu2+ single doped and Ce3+–Eu2+ co-doped KSrPO4. The enhancement of UV excitation is attributed to energy transfer from Ce3+ to Eu2+, and Ce3+ plays a role as a sensitizer. Ce3+–Eu2+ co-doped KrSrPO4 powders can possibly be applied as blue phosphors in the fields of lighting and display. 相似文献
5.
6.
S. Omelkov V. Pustovarov M. Kirm I. Ogorodnikov L. Isaenko 《Radiation measurements》2010,45(3-6):292-294
This paper reports the results of a time-resolved photoluminescence and energy transfer processes study in Ce3+ doped SrAlF5 single crystals. Several Ce3+ centers emitting near 4 eV due to 5d-4f transitions of Ce3+ ions substituting for Sr2+ in non-equivalent lattice sites were identified. The lifetime of these transitions is in the range of 25–35 ns under intra-center excitation in the energy region of 4–7 eV at T = 10 K. An effective energy transfer from lattice defects to dopant ions was revealed in the – 7–11 eV energy range. Both direct and indirect excitation channels are efficient at room temperature. Excitons bound to dopants are revealed at T = 10 K under excitation in the fundamental absorption region above 11 eV, as well as radiative decay of self-trapped excitons resulting in luminescence near 3 eV. 相似文献
7.
F. Antonangeli F. Fermi U.M. Grassano M. Piacentini A. Scacco N. Zema 《Solid State Communications》1984,49(4):323-325
Excitation spectra of pure and Tl+ doped KI have been measured at room temperature (RT) and liquid nitrogen temperature (LNT) between 13 and 30 eV. Energy transfer between the host lattice ions and the Tl+ impurities, and intrinsic recombinaton of electron-hole pairs, have been studied at different temperatures and excitation energies. Energy transfer has been observed only at RT while at LNT the intrinsic recombination, Vk centers-electrons, is the dominant process. 相似文献
8.
We investigate the spectra and scintillation properties of Ce:YA103,Ce:Y3Al5O12,and Ce:LaA103.For Ce:YAlO3,the excitation spectrum is very similar with the absorption spectrum;for Ce:Y3Al5O12 and Ce:LaAlO3,the excitation spectra are different from the absorption spectra.Further,Ce:YAlO3 has better scintillation performance than Ce:Y3Al5O12 whereas Ce:LaAlO3 has not demonstrated scintillation performance to date.We also provide reasonable explanations for these experimental phenomena from the viewpoint of energy level structure. 相似文献
9.
在980 nm近红外光激发下,通过共掺杂Ce~(3+)离子调控六方相NaLuF_4:Yb~(3+)/Ho~(3+)纳米晶体的上转换荧光发射.实验结果表明,当掺杂Ce~(3+)离子浓度从0增加到12.0%时,Ho~(3+)离子的上转换荧光发射实现了由绿光向红光的转变,其红绿比提高了近24倍.根据Ho~(3+)离子的能级结构发现,Ho~(3+)离子的红光发射源自~5F_5能级到5I8能级的辐射跃迁,因此要增强红光发射,必须提高该能级粒子数布居.Ho~(3+)与Ce~(3+)离子之间相近的能级差促使它们之间产生了共振交叉弛豫,从而有效地提高了Ho~(3+)离子~5F_5能级的粒子数布居,增强了红光发射.同时对Ho~(3+)离子的上转换调控机理进行讨论,并借助不同的激发策略,进一步证实了Ho~(3+)与Ce~(3+)离子之间相互作用的发生. 相似文献
10.
11.
12.
13.
G. M. Shapochkin V. V. Mikhailin 《Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques》2010,4(4):675-677
The spectroscopic properties of wide-band fluoride Na0.4Lu0.6F2.2 crystals activated by Ce3+ were investigated. The absorption edge for the matrix was found to be at about 9.5 eV. In the 4- to 8-eV region of the absorption
spectrum of Na0.4Lu0.6F2.2: Ce3+, all 4f-5d transitions of the Ce3+ ion are observed. In Na0.4Lu0.6F2.2: Ce3+ crystals, ultraviolet/visible emission, reflection and time-resolved vacuum ultraviolet/ultraviolet excitation spectra were
recorded at liquid helium and room temperatures. 相似文献
14.
用微波高温固相法合成了Er~(3+)单掺Lu_2O_3,Li~+与Er~(3+)共掺Lu_2O_3及Li~+,Zn~(2+),Mg~(2+)掺杂Lu_2O_3∶Er~(3+)的荧光粉。实验表明金属离子Li~+、Zn~(2+)、Mg~(2+)、Er~(3+)掺杂Lu_2O_3,不影响Lu_2O_3的立方晶相。扫描电子显微镜测量表明,Li~+掺杂可以有效改善粉体的分散性和形貌,Li~+,Zn~(2+),Mg~(2+)共掺杂获得的粉体颗粒分布更加均匀,粒径范围为80~100 nm。379 nm激发下,Li~+与Er~(3+)共掺样品发光较单掺Er~(3+)样品在565 nm处的发光增强了4.5倍,而Li~+、Zn~(2+)、Mg~(2+)与Er~(3+)共掺样品较其发光增强5.3倍。980 nm激发下,Li~+与Er~(3+)共掺样品,Li~+、Zn~(2+)、Mg~(2+)与Er~(3+)共掺样品的发光分别比单掺Er~(3+)样品在565 nm处发光增强23倍与39倍,在662 nm处发光强度分别增强20倍与43倍。379 nm激发下,较单掺Er~(3+)的样品,掺杂Li~+的样品和Li~+,Zn~(2+),Mg~(2+)和Er~(3+)共掺的样品荧光寿命均有所增加,而Zn~(2+)、Er~(3+)共掺及Mg~(2+)、Er~(3+)共掺样品的荧光寿命则有所缩短。 相似文献
15.
采用固相法制备了LiBaBO3:Ce3+发光材料.测得LiBaBO3:Ce3+材料的发射光谱为一不对称的单峰宽谱,主峰位于440 nm;监测440 nm发射峰,可得其激发光谱为一主峰位于370 nm的宽谱.利用van Uitert公式计算了Ce3+取代LiBaBO3中Ba2+时所占晶体学格位,得出438 nm发射带归属于九配位的Ce3+发射,而469 nm发射带起源于八配位的Ce3+发射.研究了Ce3+浓度对LiBaBO3:Ce3+材料发光强度的影响,结果显示,随Ce3+浓度的增大,发光强度呈现先增大后减小的趋势,Ce3+浓度为3mol%时强度最大,造成其浓度猝灭的原因为电偶极-偶极相互作用.引入Li+,Na+或K+可增强LiBaBO3:Ce3+材料的发射强度.利用InGaN管芯(370 nm)激发LiBaBO3:Ce3+材料,获得了很好的蓝白光发射,色坐标为(x=0.291,y=0.297).
关键词:
白光发光二极管
3:Ce3+')" href="#">LiBaBO3:Ce3+
晶体学格位
发光特性 相似文献
16.
An excitation band at 300 nm corresponding to Ce3+absorption is observed in pentaphosphate crystals containing Ce3+ and Nd3+ when the Nd3+ luminescence is monitored. The decay of excitation of Ce3+ in crystals of pure cerium pentaphosphate, CeP5O14, follows single exponential kinetics with a 22 ± 2 nsec lifetime. In Ce0.5Nd0.5P5O14 crystals, the Ce3+ lifetime is shortened to 3.8 ± 0.4 nsec as a result of efficient nonradiative energy transfer to the Nd3+ ions. 相似文献
17.
When crystals of CsCdBr3 are doped with trivalent cerium and thulium, it appears that Ce3+-vacancy-Tm3+ centers are formed. A very efficient cerium to thulium energy transfer is observed in this center when the doped crystals are irradiated at the energy (~ 27800 cm?1) corresponding to the 4f → 5d transition of Ce3+. Spectroscopic studies indicate that the energy transfer begins to diminish when the temperature is raised above 100 K. At room temperature the doped crystals show no detectable energy transfer. 相似文献
18.
A combination of 23Na endor and analysis of the g-values using a model of the crystal field identifies the site as comprising Ce3+ and Na+ occupying nearest neighbouring Ca2+ sites. The hyperfine interaction with the 23Na nucleus is almost entirely dipolar. 相似文献
19.
Infrared-to-visible upconverted luminescent spectra of Er3 t and La3 t codoped Y2O3 powders are investigated.By introducing La3 t ions, the upconversion green radiation is found to be greatly enhanced when compared with the powders with La3 t absent. Such enhancement can be attributed to the modification of the local symmetry surrounding the Er3 t ion, which benefits the intra-4f transitions of Er3 t ion, and the decreasing interaction between Er3 t ions, which suppresses the energy transfer process4F7∕2t 4I11∕2→ 4F9∕2t 4F9∕2. 相似文献
20.
This paper reports on a study of cross-luminescence in barium fluoride crystals doped by a variety of impurities (K+, Cd2+, Y3+, Yb3+, La3+). It is shown that doping of the crystal with a trivalent impurity gives rise to the formation of an additional cross-luminescence
band peaking at 7.5 eV, the intensity of this band increasing with increasing impurity concentration.
Original Russian Text ? A.S. Myasnikova, E.A. Radzhabov, A.V. Egranov, 2008, published in Fizika Tverdogo Tela, 2008, Vol.
50, No. 9, pp. 1582–1584. 相似文献