کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1544579 | 1512893 | 2014 | 6 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Photoexcited charge carrier dynamics in silicon nanocrystal/SiO2 superlattices
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی مواد
مواد الکترونیکی، نوری و مغناطیسی
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چکیده انگلیسی
We report in detail on the dynamics of photoexcited charge carriers in size-controlled silicon nanocrystals in silicon nanocrystal/SiO2 superlattices. The samples were prepared using plasma enhanced chemical vapor deposition and subsequent thermally induced phase separation. This unique approach allows preparation of well-defined Si nanocrystals. Experimental techniques of time-resolved absorption and photoluminescence were used to monitor the carrier dynamics on a wide time scale from picoseconds to milliseconds for a set of samples with different parameters (nanocrystal size, hydrogen annealing). The initial fast decay (tens of picoseconds) dependent on pump intensity for excitation levels exceeding one electron-hole pair per nanocrystal can be interpreted in terms of the bimolecular recombination with constant B=(2-3)Ã10â10Â cm3Â sâ1. The slow pump intensity independent decay (microseconds) can be reproduced well by a stretched-exponential function. The dependence of stretched-exponential parameters on photoluminescence photon energy and sample properties agrees well with the picture of trapped carriers.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Physica E: Low-dimensional Systems and Nanostructures - Volume 56, February 2014, Pages 177-182
Journal: Physica E: Low-dimensional Systems and Nanostructures - Volume 56, February 2014, Pages 177-182
نویسندگان
M. KoÅÃnek, M. Kozák, F. Trojánek, D. Hiller, A. Hartel, S. Gutsch, M. Zacharias, P. Malý,