The shape of size-controlled silicon nanocrystals (Si NCs) embedded in SiO 2 is investigated by tomographic energy-filtered transmission electron microscopy (EFTEM). The sphericity of the quantum dots is determined by computational analyses. In contrast to other fabrication methods, we demonstrate that the NCs in superlattices are non-agglomerated, individual clusters with slightly oblate spheroidal shape. This allows for low surface-to-volume ratios and thereby low non-radiative defect densities as required by optoelectronic or sensing applications. A near-spherical shape is also a prerequisite for the direct comparison of Si quantum dots (QDs) with theoretical simulations.
|Journal||Physica Status Solidi (C) Current Topics in Solid State Physics|
|Publication status||Published - 1 Dec 2017|
Bibliographical noteFunding Information:
We gratefully acknowledge Lena F. Kourkoutis (Cornell University) for EFTEM-tomography. This work was partially supported by the national Projects TIN2008-02903 and TIN2011-24220 of the Spanish government. We also acknowledge the financial support from the Spanish Ministry of Economy, Industry and Competitiveness through the project MAT2016-79455-P, with support of FEDER funds.
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All Science Journal Classification (ASJC) codes
- Condensed Matter Physics