Ge/Si core/shell quantum dots in alumina: tuning the optical absorption by the core and shell size
Ge/Si core/shell quantum dots (QDs) recently received extensive attention due to their specific properties induced by the confinement effects of the core and shell structure. They have a type II confinement resulting in spatially separated charge carriers, the electronic structure strongly dependent...
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Online Access: | https://doi.org/10.1515/nanoph-2016-0133 |
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doaj-0210350291804f3a9663c45dd680efd12021-09-06T19:20:30ZengDe GruyterNanophotonics2192-86142017-03-01651055106210.1515/nanoph-2016-0133nanoph-2016-0133Ge/Si core/shell quantum dots in alumina: tuning the optical absorption by the core and shell sizeNekić Nikolina0Sancho-Parramon Jordi1Bogdanović-Radović Ivančica2Grenzer Jörg3Hübner René4Bernstorff Sigrid5Ivanda Mile6Buljan Maja7Ruđer Bošković Institute, Bijenička cesta 54, 10000 Zagreb, CroatiaRuđer Bošković Institute, Bijenička cesta 54, 10000 Zagreb, CroatiaRuđer Bošković Institute, Bijenička cesta 54, 10000 Zagreb, CroatiaHelmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden, GermanyHelmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden, GermanyElettra Sincrotrone Trieste, 34149 Basovizza, ItalyRuđer Bošković Institute, Bijenička cesta 54, 10000 Zagreb, CroatiaRuđer Bošković Institute, Bijenička cesta 54, 10000 Zagreb, CroatiaGe/Si core/shell quantum dots (QDs) recently received extensive attention due to their specific properties induced by the confinement effects of the core and shell structure. They have a type II confinement resulting in spatially separated charge carriers, the electronic structure strongly dependent on the core and shell size. Herein, the experimental realization of Ge/Si core/shell QDs with strongly tunable optical properties is demonstrated. QDs embedded in an amorphous alumina glass matrix are produced by simple magnetron sputtering deposition. In addition, they are regularly arranged within the matrix due to their self-assembled growth regime. QDs with different Ge core and Si shell sizes are made. These core/shell structures have a significantly stronger absorption compared to pure Ge QDs and a highly tunable absorption peak dependent on the size of the core and shell. The optical properties are in agreement with recent theoretical predictions showing the dramatic influence of the shell size on optical gap, resulting in 0.7 eV blue shift for only 0.4 nm decrease at the shell thickness. Therefore, these materials are very promising for light-harvesting applications.https://doi.org/10.1515/nanoph-2016-0133ge/si core/shell quantum dotsquantum confinementabsorptionself-assembly |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Nekić Nikolina Sancho-Parramon Jordi Bogdanović-Radović Ivančica Grenzer Jörg Hübner René Bernstorff Sigrid Ivanda Mile Buljan Maja |
spellingShingle |
Nekić Nikolina Sancho-Parramon Jordi Bogdanović-Radović Ivančica Grenzer Jörg Hübner René Bernstorff Sigrid Ivanda Mile Buljan Maja Ge/Si core/shell quantum dots in alumina: tuning the optical absorption by the core and shell size Nanophotonics ge/si core/shell quantum dots quantum confinement absorption self-assembly |
author_facet |
Nekić Nikolina Sancho-Parramon Jordi Bogdanović-Radović Ivančica Grenzer Jörg Hübner René Bernstorff Sigrid Ivanda Mile Buljan Maja |
author_sort |
Nekić Nikolina |
title |
Ge/Si core/shell quantum dots in alumina: tuning the optical absorption by the core and shell size |
title_short |
Ge/Si core/shell quantum dots in alumina: tuning the optical absorption by the core and shell size |
title_full |
Ge/Si core/shell quantum dots in alumina: tuning the optical absorption by the core and shell size |
title_fullStr |
Ge/Si core/shell quantum dots in alumina: tuning the optical absorption by the core and shell size |
title_full_unstemmed |
Ge/Si core/shell quantum dots in alumina: tuning the optical absorption by the core and shell size |
title_sort |
ge/si core/shell quantum dots in alumina: tuning the optical absorption by the core and shell size |
publisher |
De Gruyter |
series |
Nanophotonics |
issn |
2192-8614 |
publishDate |
2017-03-01 |
description |
Ge/Si core/shell quantum dots (QDs) recently received extensive attention due to their specific properties induced by the confinement effects of the core and shell structure. They have a type II confinement resulting in spatially separated charge carriers, the electronic structure strongly dependent on the core and shell size. Herein, the experimental realization of Ge/Si core/shell QDs with strongly tunable optical properties is demonstrated. QDs embedded in an amorphous alumina glass matrix are produced by simple magnetron sputtering deposition. In addition, they are regularly arranged within the matrix due to their self-assembled growth regime. QDs with different Ge core and Si shell sizes are made. These core/shell structures have a significantly stronger absorption compared to pure Ge QDs and a highly tunable absorption peak dependent on the size of the core and shell. The optical properties are in agreement with recent theoretical predictions showing the dramatic influence of the shell size on optical gap, resulting in 0.7 eV blue shift for only 0.4 nm decrease at the shell thickness. Therefore, these materials are very promising for light-harvesting applications. |
topic |
ge/si core/shell quantum dots quantum confinement absorption self-assembly |
url |
https://doi.org/10.1515/nanoph-2016-0133 |
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