کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5492182 1525143 2017 17 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Stokes shift and fine structure splitting in composition-tunable ZnxCd1−xSe nanocrystals: Atomistic tight-binding theory
موضوعات مرتبط
مهندسی و علوم پایه فیزیک و نجوم فیزیک ماده چگال
پیش نمایش صفحه اول مقاله
Stokes shift and fine structure splitting in composition-tunable ZnxCd1−xSe nanocrystals: Atomistic tight-binding theory
چکیده انگلیسی
I report on the atomistic correlation of the structural properties and excitonic splitting of ternary alloy ZnxCd1−xSe wurtzite nanocrystals using the sp3s* empirical tight-binding method with the description of the first nearest neighbouring interaction and bowing effect. Based on a successful model, the computations are presented under various Zn compositions (x) and diameters of alloy ZnxCd1−xSe nanocrystals with the experimentally synthesized compositions and sizes. With increasing Zn contents (x), the optical band gaps and electron-hole coulomb energies are improved, while ground electron-hole wave function overlaps, electron-hole exchange energies, stokes shift and fine structure splitting are reduced. A composition-tunable emission from blue to yellow wavelength is obviously demonstrated. The optical band gaps, ground electron-hole wave function overlaps, electron-hole interactions, stokes shift and fine structure splitting are progressively decreased with the increasing diameters. Alloy ZnxCd1−xSe nanocrystal with Zn rich and large diameter is the best candidate to optimistically be used as a source of entangled photon pairs. The agreement with the experimental data is remarkable. Finally, the present systematic study on the structural properties and excitonic splitting predominantly opens a new perspective to understand the size- and composition-dependent properties of ZnxCd1−xSe nanocrystals with a comprehensive strategy to design the optoelectronic devices.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Physica B: Condensed Matter - Volume 506, 1 February 2017, Pages 192-197
نویسندگان
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