کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5398566 | 1505884 | 2016 | 8 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Luminescent, optical and electronic properties of La3Ta0.5Ga5.5O14 single crystals grown in different atmospheres
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی تئوریک و عملی
پیش نمایش صفحه اول مقاله

چکیده انگلیسی
Luminescent, optical and electronic properties of La3Ta0.5Ga5.5O14 single crystals grown in different atmospheres are presented. The absorption bands at 255, 290, 350 and 480Â nm were detected; the intensity of bands increases with the concentration of oxygen in the growth atmosphere. It is shown that the shift of the fundamental absorption edge with the temperature obeys Urbach rule. The corresponding fitting allowed to estimate the slope coefficient Ï=0.35, which implies self-trapping of excitons in La3Ta0.5Ga5.5O14. Calculations of the band structure, partial densities of states and reflectivity spectra were performed. The bandgap of La3Ta0.5Ga5.5O14 was determined as Eg=5.6Â eV. The luminescence properties under UV, VUV and X-ray excitation were studied. Intrinsic emission band at 440-450Â nm is attributed to the excitons self-trapped at TaO6 molecular complexes. Extrinsic emission bands at 410, 440 and 550Â nm are attributed to the emission of excitons trapped by antisite defects, F-centers and oxygen deficient oxyanionic complexes.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Luminescence - Volume 177, September 2016, Pages 152-159
Journal: Journal of Luminescence - Volume 177, September 2016, Pages 152-159
نویسندگان
D.A. Spassky, M.G. Brik, N.S. Kozlova, A.P. Kozlova, E.V. Zabelina, O.A. Buzanov, A. Belsky,