| 1. |
- Sychugov, Ilya, et al.
(författare)
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Luminescent silicon nanocrystals as downconverters for photovoltaic and lighting applications
- 2016
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Ingår i: Asia Communications and Photonics Conference, ACP. - : OSA - The Optical Society.
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Konferensbidrag (refereegranskat)abstract
- Nanocrystals offer new functionalities for optoelectronics. Ensemble and single-dot measurements of chemically-synthesized silicon nanocrystals revealed high quantum yield, narrow homogeneous linewidth, and large Stokes shift, confirming application feasibility for these non-toxic and abundant material nanoparticles. Asia Communications and Photonics Conferene (ACP)
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| 2. |
- Sychugov, Ilya, et al.
(författare)
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Single-dot absorption spectroscopy and theory of silicon nanocrystals
- 2016
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Ingår i: Physical Review B. - : American Physical Society. - 2469-9950. ; 93:16
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Tidskriftsartikel (refereegranskat)abstract
- Photoluminescence excitation measurements have been performed on single, unstrained oxide-embedded Si nanocrystals. Having overcome the challenge of detecting weak emission, we observe four broad peaks in the absorption curve above the optically emitting state. Atomistic calculations of the Si nanocrystal energy levels agree well with the experimental results and allow identification of some of the observed transitions. An analysis of their physical nature reveals that they largely retain the indirect band-gap structure of the bulk material with some intermixing of direct band- gap character at higher energies.
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| 3. |
- Sychugov, Ilya, et al.
(författare)
-
Strong Absorption Enhancement in Si Nanorods
- 2016
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Ingår i: Nano letters (Print). - : American Chemical Society (ACS). - 1530-6984 .- 1530-6992. ; 16:12, s. 7937-7941
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Tidskriftsartikel (refereegranskat)abstract
- We report two orders of magnitude stronger absorption in silicon nanorods relative to bulk in a wide energy range. The local field enhancement and dipole matrix element contributions were disentangled experimentally by single-dot absorption measurements on differently shaped particles as a function of excitation polarization and photon energy. Both factors substantially contribute to the observed effect as supported by simulations of the light-matter interaction and atomistic calculations of the transition matrix elements. The results indicate strong shape dependence of the quasidirect transitions in silicon nanocrystals, suggesting nanostructure shape engineering as an efficient tool for overcoming limitations of indirect band gap materials in optoelectronic applications, such as solar cells.
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