Effects of inter-nanocrystal distance on luminescence quantum yield in ensembles of Si nanocrystals

Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F14%3A10286201" target="_blank" >RIV/00216208:11320/14:10286201 - isvavai.cz</a>
Result on the web
<a href="http://dx.doi.org/10.1063/1.4904472" target="_blank" >http://dx.doi.org/10.1063/1.4904472</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1063/1.4904472" target="_blank" >10.1063/1.4904472</a>

Result language
angličtina
Original language name
Effects of inter-nanocrystal distance on luminescence quantum yield in ensembles of Si nanocrystals
Original language description
The absolute photoluminescence (PL) quantum yield (QY) of multilayers of Silicon nanocrystals (SiNCs) separated by SiO2 barriers were thoroughly studied as function of the barrier thickness, excitation wavelength, and temperature. By mastering the plasma-enhanced chemical vapor deposition growth, we produce a series of samples with the same size-distribution of SiNCs but variable interlayer barrier distance. These samples enable us to clearly demonstrate that the increase of barrier thickness from similar to 1 to larger than 2 nm induces doubling of the PL QY value, which corresponds to the change of number of close neighbors in the hcp structure. The temperature dependence of PL QY suggests that the PL QY changes are due to a thermally activated transport of excitation into non-radiative centers in dark NCs or in the matrix. We estimate that dark NCs represent about 68% of the ensemble of NCs. The PL QY excitation spectra show no significant changes upon changing the barrier thickness
Czech name
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Czech description
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Type
J<sub>x</sub> - Unclassified - Peer-reviewed scientific article (Jimp, Jsc and Jost)
CEP classification
BH - Optics, masers and lasers
OECD FORD branch
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Project
<a href="/en/project/7E11021" target="_blank" >7E11021: Silicon Nanodots for Solar Cell Tandem</a><br>
Continuities
P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year
2014
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

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