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1.
The luminescence spectra of thin films of PbWO4 and Bi2WO6 were investigated. It is shown that these spectra are similar and that they consist of three individual bands in the blue (2.80 eV PbWO4 and 2.93 eV Bi2WO6), green (2.35 eV PbWO4 and Bi2WO6), and red (1.75 eV PbWO4 and 1.90 eV Bi2WO6) spectral regions. The differences in the nature of the absorption centers of excitation energy are established. The distinguishing features displayed by the temperature dependences of the individual emission bands in the PbWO4 films are explained by energy migration between emission centers via transfer of free carriers through the conduction and valence bands. 相似文献
2.
O. M. Bordun 《Journal of Applied Spectroscopy》2001,68(6):974-978
Luminescence spectra of thin Bi4Ge3O12 films annealed in air and in vacuum have been investigated. It has been established that the luminescence spectra for different forms of excitation consist of three bands with maxima at 2.70, 2.40, and 2.05 eV. The relation of the bands with maxima at 2.40 and 2.05 eV to the centers that incorporate an oxygen vacancy has been shown. The separated emission bands have been interpreted. 相似文献
3.
The luminescence and luminescence excitation spectra of thin films of Bi4Ge3O12 and Bi2Ge3O9 were investigated. The spectra were decomposed into elementary components by the Alentsev-Fok method. It has been established
that the luminescence spectra of thin Bi4Ge3O12 and Bi2Ge3O9 films have a similar structure and that each contains three luminescence bands with maxima at 2.70, 2.40, and 2.05 eV and
at 2.73, 2.40, and 1.95 eV, respectively. Comparison of the results obtained with the well-known results of investigation
of the luminescence of Bi12GeO20 and Bi2O3 suggests that the luminescence in the compounds considered is caused by the radiation processes that proceed in structural
complexes of similar configuration that contain the bismuth ion in the nearest oxygen environment.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 72, No. 3, pp. 377–380, May–June, 2005. 相似文献
4.
The spectra of IR reflection of the systems thin Bi4Ge3O12 film–substrate made of molten -SiO2 quartz in the region 10–1600 cm–1 at 295 K are investigatedterpretation of fundamental vibrations in the region 10–800 cm–1 and two phonon processes in the region 800–1600 cm–1 are considered. 相似文献
5.
O. M. Bordun 《Journal of Applied Spectroscopy》2002,69(3):430-433
Luminescence spectra of Y2O3 thin films annealed in air and in vacuum are investigated. It is established that the presence of oxygen vacancies leads to a decrease in the intensity of the luminescence band with a maximum at 3.4 eV (related to emission of selflocalized Frenkel excitons describing the excited state of a molecular ion (YO6)9–) and of the luminescence band with a maximum at 2.9 eV (related to the anion sublattice). It is revealed that the oxygen vacancies also lead to a decrease in the luminescence intensity in the 2.60, 2.35, 2.10. 1.90, and 1.70 eV bands that are related to radiative recombination in the donor–acceptor Y3+–O2– pairs. The donor–acceptor distances are calculated. 相似文献
6.
Based on the temperature dependence of the fundamental absorption edge of thin PbWO4 films, we studied the exciton–phonon interaction, which made it possible to interpret the absorption edge as the absorption of autolocalized excitons. The temperature dependence of the forbidden band gap is investigated. 相似文献
7.
纳米ZnO薄膜的激子光致发光特性 总被引:3,自引:2,他引:1
报道了纳米ZnO薄膜激子光致发光(PL)与温度的关系。首先利用低压金属有机化学气相沉积(LPMOCVD)技术生长ZnS薄膜,然后将ZnS薄膜在氧气中于800℃下热氧化2h获得纳米ZnO薄膜。X射线衍射(XRD)结果表明,纳米ZnO薄膜具有六角纤锌矿多晶结构且具有择优(002)取向。室温下观察到一束强的紫外(326eV)光致发光(PL)和很弱的深能级(DL)发射。根据激子峰的半高宽(FWHM)与温度的关系,确定了激子纵向光学声子(LO)的耦合强度(ГLO)。 相似文献
8.
结合XRD和原子力显微镜等方法,利用椭圆偏振光谱仪测试了单层SiO2薄膜(K9基片)和单层HfO2薄膜(K9基片)的椭偏参数,并用Sellmeier模型和Cauchy模型对两种薄膜进行拟合,获得了SiO2薄膜和HfO2薄膜在300-800nm波段内的色散关系。用X射线衍射仪确定薄膜结构,并用原子力显微镜观察薄膜的微观形貌,分析表明:SiO2薄膜晶相结构呈现无定型结构,HfO2薄膜的晶相结构呈现单斜相结构;薄膜光学常数的大小和薄膜的表面形貌有关;Sellmeier和Cauchy模型较好地描述了该波段内薄膜的光学性能,并得到薄膜的折射率和消光系数等光学常数随波长的变化规律。 相似文献
9.
Thermostimulated luminescence (TSL) of PbWO4, Bi2WO6, and Y2WO6 ceramics on x-ray excitation is investigated. The spectral luminosity of the thermostimulated luminescence is analyzed. The thermal activation energies conforming to the corresponding thermostimulated luminescence peaks are determined. It is established that on emptying trapping centers radiative recombination occurs at the intrinsic-luminescence centers associated with tungsten-oxygen complexes WO4
2–. 相似文献
10.
O. M. Bordun I. I. Kukharskii V. V. Dmitruk Yu. B. Kotsan 《Journal of Applied Spectroscopy》2006,73(5):667-671
We have studied the luminescence spectra and luminescence excitation spectra of Pb2Bi6O11 and Sn2Bi6O11 ceramics at 80 K. We have used the Alentsev-Fock to decompose the spectra into elementary components. We have established
that the luminescence spectra of Pb2Bi6O11 and Sn2Bi6O11 ceramics contain three elementary bands each with maxima at 2.60, 2.32, 12.93 eV and 2.62, 2.30, 2.00 eV. Comparison of the
data obtained with the results of a study of the luminescence spectra for a series of bismuth-containing oxide compounds suggest
that luminescence of Pb2Bi6O11 and Sn2Bi6O11 is due to radiative processes in structural complexes containing a bismuth ion in a nearest-neighbor oxygen environment.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 5, pp. 597–600, September–October, 2006. 相似文献
11.
O. M. Bordun 《Journal of Applied Spectroscopy》1998,65(1):149-151
Luminescence spectra of thin films of PbWO4 and Bi2WO6 are invesigated. The Alentsev-Fock method is used to separate the spectra into elementary components. The emission bands
with maxima at 2.8 eV in PbWO4 and at 2.93 eV in Bi2WO6 luminescence spectra are interpreted as the emission of self-localized Frenkel excitons. The bands with maxima at 2.35 and
1.75 eV in PbWO4 and at 2.35 and 1.9 eV in Bi2WO6 are related to oxygen vacancies.
L’vov State University, 50, Dragomanov St., L'vov, 290005, Ukraine. Translated from Zhurnal Prikladnoi Spektroskopii, Vol.
65, No. 1, pp. 143–145, January–February, 1998. 相似文献
12.
Gd2O3:Eu3+溶胶-凝胶薄膜发光特性研究 总被引:7,自引:2,他引:5
以无机稀土氧化物为原料制备了Gd2O3:Eu3 溶胶-凝胶薄膜,通过对不同Eu3 离子掺杂浓度、不同烧结温度薄膜发光强度的研究,得出Gd2O3薄膜中Eu3 离子的最佳掺杂浓度为10%、最佳热处理工艺为800℃下烧结2h;由薄膜和粉末激发谱的比较发现:薄膜中存在着比粉末更有效的能量传递,从而更有利于高能射线激发发光;首次观察到薄膜经过1000℃烧结2h后发光消失,并通过SEM和XRD的实验分析对这一现象进行了解释。 相似文献
13.
用电子束蒸发法制备出四种不同Y2O3含量的Y2O3稳定ZrO2(YSZ)薄膜,用X射线衍射和透射光谱测定薄膜的结构和光学性能.结果表明:随着Y2O3含量的增加,ZrO2薄膜从单斜相向高温相(四方相和立方相)转变,获得了结构稳定的YSZ薄膜;YSZ薄膜的晶粒尺寸都比ZrO2薄膜的大,但随着Y2O3加入量的增加,晶粒尺寸有减小的趋势,薄膜表面也趋向光滑平整.所有YSZ薄膜的透射谱线都与ZrO2薄膜相似,在可见光和红外光区都有较高的透过率.Y2O3的加入还可以改变薄膜的折射率,在一定范围内可得到所需的任意折射率. 相似文献
14.
Luminescence spectra and photoluminescence excitation spectra of Y2O3:Bi and Y3Al5O12:Bi thin films were investigated. Luminescence was stimulated by the emission from two types of centers that were associated
with the substitution of Bi3+ for Y3+ in sites of the crystal lattice of Y2O3 (Y3Al5O12) with point symmetries C2 and C3i (D2 and C3i). The emission of Bi3+ in the site with point symmetry C3i causes blue luminescence in both Y2O3:Bi and Y3Al5O12:Bi films with maxima at 3.03 eV and 3.15 eV, respectively, that is related to the 3P1-1S0 transition. The emission of Bi3+ in the site with point symmetry C2 gives green luminescence in Y2O3:Bi with the maximum at 2.40 eV that is also related to the 3P1-1S0 transition. The emission of Bi3+ in the site with point symmetry D2 leads to ultraviolet luminescence in Y3Al5O12:Bi with the maximum at 3.75 eV that corresponds to the 3P1-1S0 transition. The red luminescence band with the maximum at 1.85 eV in Y2O3:Bi is due to the presence of structural defects.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 75, No. 2, pp. 202–207, March–April, 2008. 相似文献
15.
溶胶—凝胶法制备CdS微晶掺杂TiO2/SiO2薄膜及其非线性光学特性 总被引:3,自引:1,他引:2
采用溶胶-凝胶方法在普通的载玻片上制备了CdS微晶掺杂的TiO2/SiO2复合薄膜。用正硅酸乙酯、钛酸丁酯、醋酸镉作原料,比较了两种硫化剂:硫尿和硫代乙酰氨的硫化作用。X射线衍射谱和拉曼光谱揭示了CdS微晶镶嵌在TiO2/SiO2薄膜的玻璃网络中。不同热处理温度、不同热处理时间的吸收光谱表明薄膜中存在着量子尺寸效应。采用Z扫描技术测量了薄膜的非线性吸收及非线性折射率n2=-4.67×10-7esu。 相似文献
16.
17.
Sc2O3 luminescence spectra are studied. The spectra are separated into elementary bands by the Alentsev–Fock method. It is established
that the luminescence spectra consist of a number of overlapping bands with maxima at 3.5; 3.05; 2.65; 2.35, and 2.05 eV.
The band at 3.5 eV is interpreted as emission of self-localized excitons, and the other bands, as defect-center recombination.
L’vov State University, 50, Dragomanov St., L’vov, 290005, Ukraine. Translated from Zhurnal Prikladnoi Spektroskopii, Vol.
64, No. 6, pp. 776–778, November–December, 1997. 相似文献
18.
采用倾斜式生长的方法,在本底真空为3×10-4 Pa,生长率为0.2 nm·s-1的条件下,通过改变衬底的法线方向与入射粒子流的夹角α,在ITO导电玻璃衬底上制备了ZnS纳米薄膜。在α=80°和85°时,样品的X射线衍射谱证实了不同倾斜角时所制备薄膜中均有纳米ZnS晶体形成,扫描电子显微镜(SEM)图像显示,所形成的薄膜均呈现出了柱状结构,并且倾斜角为85°时所得到的纳米柱直径大于80°时所得结果;在α=0°时,相应测量结果表明,虽然在不同衬底上也形成了纳米ZnS晶体薄膜,但并未见柱状结构,而是形成了一层均匀且致密的薄膜。对两种薄膜结构的生长动力学过程作了分析。ITO衬底上薄膜的透射光谱表明ZnS柱状薄膜能够提高可见光的透过率,因此对柱状ZnS纳米薄膜的研究将有利于提高电致发光器件的发光效率。 相似文献
19.
Raman and IR spectra of Bi2W2O9, the m = 2 member of the cation‐deficient Aurivillius phase, have been measured. The obtained spectra are discussed using the factor group approach for the orthorhombic Pna21(C2v9) space group. The results are compared with those obtained for Bi2WO6 and some m = 2 members of Aurivillius family of bismuth layered ferroelectrics. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
20.
利用溶液法制备了以HfSiOx为绝缘层、HfInZnO为有源层、Al_2O_3为界面修饰层的TFT器件。HfSiOx薄膜经Al_2O_3薄膜修饰后,薄膜表面粗糙度从0.24nm降低至0.16nm。Al2O3薄膜与HfSiOx薄膜之间的界面接触良好,以Al_2O_3为界面修饰层的TFT器件整体性能得到提升,具体表现为:栅极电压正向和反向扫描过程中产生的阈值电压漂移显著减小,器件的阈值电压和亚阈值摆幅降低,迁移率与开关比增大。研究证明,溶液法制备Al_2O_3薄膜适合作为改善器件性能的界面修饰层。 相似文献