Step-like increase of quantum yield of 1.5 μm Er-related emission in SiO{sub 2} doped with Si nanocrystals

Journal Article · Sat Feb 14 00:00:00 EST 2015 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4907759· OSTI ID:22413096

Saeed, S.; Gregorkiewicz, T. ^[1]

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1. Van der Waals-Zeeman Institute, University of Amsterdam, Science Park 904, NL-1098 XH Amsterdam (Netherlands)

We investigate the excitation dependence of the efficiency of the Si nanocrystals-mediated photoluminescence from Er{sup 3+} ions embedded in a SiO{sub 2} matrix. We show that the quantum yield of this emission increases in a step-like manner with excitation energy. The subsequent thresholds of this characteristic dependence are approximately given by the sum of the Si nanocrystals bandgap energy and multiples of 0.8 eV, corresponding to the energy of the first excited state of Er{sup 3+} ions. By comparing differently prepared materials, we explicitly demonstrate that the actual values of the threshold energies and the rate of the observed increase of the external quantum yield depend on sample characteristics—the size, the optical activity and the concentration of Si nanocrystals as well Er{sup 3+} ions to Si nanocrystals concentration ratio. In that way, detailed insights into the efficient excitation of Er{sup 3+} ions are obtained. In particular, the essential role of the hot-carrier-mediated Er excitation route is established, with a possible application perspective for highly efficient future-generation photovoltaics.

• OSTI ID: 22413096
• Journal Information: Journal of Applied Physics, Vol. 117, Issue 6; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
APPROXIMATIONS
CHARGE CARRIERS
COMPARATIVE EVALUATIONS
CONCENTRATION RATIO
DOPED MATERIALS
ERBIUM IONS
EV RANGE
EXCITATION
EXCITED STATES
MATRIX MATERIALS
NANOSTRUCTURES
OPTICAL ACTIVITY
PHOTOLUMINESCENCE
PHOTOVOLTAIC EFFECT
SILICON
SILICON OXIDES
THRESHOLD ENERGY