کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1485048 1510529 2008 5 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Conformational heterogeneity of the point defects in silica: The lifetime of the phosphorescence band at 2.7 eV
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد سرامیک و کامپوزیت
پیش نمایش صفحه اول مقاله
Conformational heterogeneity of the point defects in silica: The lifetime of the phosphorescence band at 2.7 eV
چکیده انگلیسی
We have measured the excitation and emission energy dependence of the lifetimes of the 2.7 eV photoluminescence band associated to oxygen deficient centers in silica glasses. The non-exponential behavior of this time decay is consistent with intrinsic conformational heterogeneity of these point defects in the amorphous matrix. Accordingly, we have analyzed the data in terms of a radiative rates distribution. Moreover, both surface and bulk typologies of these point defects have been studied. The mean value of the lifetime distribution of the surface defects increases from 12 to 15 ms varying the excitation energy from 4.6 to 5.2 eV, and it increases from 14 to 15 ms in the emission energy interval between 2.6 and 3.0 eV. As well similar variations of the lifetime are observed for interior defects, when measured at different excitation and emission energies. We can also estimate the width of the lifetime distribution of this ensemble of point defects in silica glass.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Non-Crystalline Solids - Volume 354, Issues 2–9, 15 January 2008, Pages 239-243
نویسندگان
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