کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
8148099 1524157 2018 5 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Resonant Raman scattering from CdTe/ZnTe self-assembled quantum dot structures
موضوعات مرتبط
مهندسی و علوم پایه فیزیک و نجوم فیزیک ماده چگال
پیش نمایش صفحه اول مقاله
Resonant Raman scattering from CdTe/ZnTe self-assembled quantum dot structures
چکیده انگلیسی
We report resonant Raman scattering results of CdTe/ZnTe self-assembled quantum dot (QD) structures. Photoluminescence spectra reveal that the band gap energies of the CdTe QDs decrease with the increase of CdTe thickness from 2.0 to 3.5 monolayers, which indicates that the size of the QDs increases. When the CdTe/ZnTe QD structures are excited by non-resonant excitation, a longitudinal optical (LO) phonon response from the ZnTe barrier material is observed at 206 cm−1. In contrast, when the CdTe/ZnTe QD structures are resonantly excited near the band gap energy of the QDs, additional phonon modes emerge at 167 and 200 cm−1, while the ZnTe LO phonon response completely disappears. The 167 cm−1 mode corresponds to the LO phonon of the CdTe QDs. A spatially resolved Raman scattering from the cleaved edge of the QD sample reveals that the 200 cm−1 mode is strongly localized at the interface between the CdTe QDs and ZnTe cap layer. This phonon mode is attributed to the interface optical (IO) phonon. The analytically calculated value of the IO phonon energy using a dielectric continuum approach, assuming a spherical dot boundary, agrees well with the experimental value.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Current Applied Physics - Volume 18, Issue 2, February 2018, Pages 267-271
نویسندگان
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