کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1810830 1025573 2012 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Optoelectronic properties of LixAxNbO3 (A=Na, K, Rb, Cs, Fr) crystals
موضوعات مرتبط
مهندسی و علوم پایه فیزیک و نجوم فیزیک ماده چگال
پیش نمایش صفحه اول مقاله
Optoelectronic properties of LixAxNbO3 (A=Na, K, Rb, Cs, Fr) crystals
چکیده انگلیسی
The structural and optoelectronic properties of LixAxNbO3 (A=Na, K, Rb, Cs, Fr and x=0, 0.5) compounds have been investigated by the generalized gradient approximation within density functional theory. The calculated fundamental direct band gap of pure LiNbO3 is 3.32 eV. It is found that the substitution of alkali elements drastically change the optoelectronic nature of the compound from direct to indirect bandgap semiconductor and the fundamental gap also decreases. The nature of the compound is ionic with strong bonds between alkali ions and O, while there are partial covalent bonds between Nb and O. The calculated static refractive index of pure LiNbO3 is 2.43 for the perpendicular plane to the c-axis, while 2.37 for the parallel plane to the c-axis. So these values are intensively dependent on the substitution of alkali metals. The calculated electron energy loss spectra are in good agreement with the experimental results. It also predicts some extra interesting peaks, which have not been observed in experiments.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Physica B: Condensed Matter - Volume 407, Issue 3, 1 February 2012, Pages 368-377
نویسندگان
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