Phonon-assisted radiative electron-hole recombination in silicon quantum dots

The recombination processes leading to tunneling afterglow and photostimulated luminescence were studied in systems based on ionic host crystals with low-dimensional structures (semiconductor quantum dots) formed as a result of the self-organized growth. The systems of AgBr nanocrystals embedded into the KBr crystal lattice and CsPbBr 3 nanocrystals embedded into the CsBr crystal lattice were investigated. The energy of electron–hole recombination in matrices was shown to transfer to quantum dots. To identify the structure of recombining electron and hole centers, magnetic resonance detected optically by monitoring the tunneling afterglow was used.

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Effect of Heterojunction on Exciton Binding Energy and Electron–Hole Recombination Probability in CdSe/ZnS Quantum Dots

Journal of Chemical Theory and Computation ◽

10.1021/ct500548x ◽

2015 ◽

Vol 11 (2) ◽

pp. 462-471 ◽

Cited By ~ 10

Author(s):

Jennifer M. Elward ◽

Arindam Chakraborty

Keyword(s):

Quantum Dots ◽

Binding Energy ◽

Exciton Binding Energy ◽

Electron Hole ◽

Recombination Probability ◽

Hole Recombination

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Hydrothermal Synthesis and Photocatalytic Performance of Ag Quantum Dots Sensitized Bi4Ti3O12 Nanobelts

NANO ◽

10.1142/s1793292015500204 ◽

2015 ◽

Vol 10 (02) ◽

pp. 1550020 ◽

Cited By ~ 3

Author(s):

Xue Lin ◽

Xiaoyu Guo ◽

Di Liu ◽

Qingwei Wang ◽

Yongsheng Yan

Keyword(s):

Quantum Dots ◽

Photocatalytic Activity ◽

Rhodamine B ◽

High Photocatalytic Activity ◽

Contact Interface ◽

Electron Hole ◽

Photoexcited Electron ◽

Intimate Contact ◽

Composite Photocatalyst ◽

Hole Recombination

Ag / Bi 4 Ti 3 O 12 heterostructure with high photocatalytic activity was synthesized via a simple and practical hydrothermal method by using Bi 4 Ti 3 O 12 nanobelts as substrate materials. The as-prepared Ag / Bi 4 Ti 3 O 12 heterostructure included Ag quantum dots assembling uniformly on the surface of Bi 4 Ti 3 O 12 nanobelts. Comparing with pure Bi 4 Ti 3 O 12 nanobelts, the composite photocatalyst exhibited enhanced photocatalytic activity under visible light irradiation in the decomposition of rhodamine B aqueous solution. The enhancement performance is believed to be induced by the intimate contact interface, where silver quantum dots serve as good electron acceptor for facilitating quick photoexcited electron transfer and thus decreasing electron-hole recombination. It was also found that the photodegradation of rhodamine B molecules is mainly attributed to the oxidation action of the generated [Formula: see text] radicals.

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Line Shape in Resonance Raman Scattering from Silicon Quantum Dots

MRS Proceedings ◽

10.1557/proc-571-235 ◽

1999 ◽

Vol 571 ◽

Cited By ~ 2

Author(s):

R.K. Soni ◽

L.F. Fonseca ◽

O. Resto ◽

S.Z. Weisz ◽

S. Tripathy

Keyword(s):

Quantum Dots ◽

Raman Scattering ◽

Size Distribution ◽

Line Shape ◽

Quartz Substrate ◽

Resonance Raman ◽

Visible Region ◽

Electron Hole ◽

Silicon Quantum Dots ◽

Raman Study

ABSTRACTWe have carried out a resonance Raman study of line-shape in silicon quantum dots synthesized on a quartz substrate by co-sputtering bulk Si and Si02. Optical transmission measurements are used to evaluate dot size distribution. The size distribution shows peaks around 1.0 and 1.4 nm. The Si dots exhibit photoluminescence in the visible region, which shifts to higher energy with decreasing size. The size dependence of Raman scattering shows phonon softening and increasing asymmetrical broadening for small dots (< 2nm). The observed spectra are compared with calculations considering electron-hole interactions at a quasi-direct gap of a spherical quantum dot.

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