کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1490840 992334 2010 4 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Dynamics of energy absorption versus crystallization in Bi4Ge3O12 (BGO) amorphous materials
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد سرامیک و کامپوزیت
پیش نمایش صفحه اول مقاله
Dynamics of energy absorption versus crystallization in Bi4Ge3O12 (BGO) amorphous materials
چکیده انگلیسی

Theoretical and experimental determinations show that the intrinsic luminescence of BGO materials is strongly influenced by GeO4− tetrahedra around Bi3+ ions. Besides Bi3+ transitions, the excitonic spectra mask the BGO bandgap. Theoretical computations give the bandgap at 5.19 eV compared with the experimental one at 5.17 eV in BGO crystals and a significant decrease at 3.26 eV in the amorphous materials. This is due to the high disordering of the GeO4− tetrahedral which also reduces the refractive index of the amorphous materials. Formation of excitonic states and their overlap with the Bi3+ transitions suggests that the energy absorption takes place via the p-electrons of the O2− ions and is then transferred to the Bi3+p-electrons (excited states) close to the conduction band. Light emission appears after de-excitation to the ground state.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Materials Research Bulletin - Volume 45, Issue 10, October 2010, Pages 1492–1495
نویسندگان
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