Journal ArticleDOI
Fine structure and selection rules for excitonic transitions in silicon nanostructures
TLDR
In this paper, the excitonic fine structure, including splitting due to direct and exchange interactions, has been resolved from silicon nanocrystals and from silicon norods, and the results are analyzed in terms of spin and orbital selection rules indicating that the dimensionality of the exciton determines the relative contribution of the direct Coulomb and the exchange interactions in these nanostructures.Abstract:
The excitonic fine structure, including splitting due to direct and exchange interactions, has experimentally been resolved from silicon nanocrystals and from silicon nanorods. We have found the hierarchy of levels for silicon nanorods to be different from that of silicon nanocrystals with the slower semidark state located above the faster semibright state. The results are analyzed in terms of spin and orbital selection rules indicating that the dimensionality of the exciton determines the relative contribution of the direct Coulomb and the exchange interactions in these nanostructures.read more
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Observation of the dark exciton in CdSe quantum dots
TL;DR: In this article, the authors used external magnetic fields to identify the band edge emitting statc in CdSe quantum dms and calculated the band-edge exciton structure, including the effects of the electron-hole exchange interaction and a nonspherical shape.
Journal ArticleDOI
Theory of excitons in cubic III-V semiconductor GaAs, InAs and GaN quantum dots: Fine structure and spin relaxation
TL;DR: In this article, the spin relaxation in cubic III-V semiconductor GaAs, InAs and GaN quantum dots is investigated systematically and the exciton spin relaxation is calculated by first setting up the effective exciton Hamiltonian.
Journal ArticleDOI
Doped and codoped silicon nanocrystals: The role of surfaces and interfaces
TL;DR: In this paper, the authors summarize the latest progress in this fascinating research field considering free-standing and matrix-embedded Si nanocrystals both from the theoretical and experimental point of view, with special attention given to the results obtained by ab-initio calculations and to size-, surface- and interface-induced effects.
Journal ArticleDOI
Radiative and nonradiative relaxation phenomena in hydrogen- and oxygen-terminated porous silicon
Neta Arad-Vosk,Amir Sa'ar +1 more
TL;DR: It is shown that radiative processes should be linked with quantum confinement in small Si nanocrystallites and are not affected by oxidation and nonradiative relaxation processes are associated with the state of oxidation where slower relaxation times characterize hydrogen-terminated porous silicon.
Journal ArticleDOI
Doped and Codoped Silicon Nanocrystals: the Role of Surfaces and Interfaces
TL;DR: In this article, the authors summarize the latest progress in this fascinating research field considering free-standing and matrix-embedded Si nanocrystals both from the theoretical and experimental point of view, with special attention given to the results obtained by ab-initio calculations and to size-, surface- and interface-induced effects.
References
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Journal ArticleDOI
Excitons in nanoscale systems
Gregory D. Scholes,Garry Rumbles +1 more
TL;DR: A cross-disciplinary review of the essential characteristics of excitons in nanoscience is presented, highlighting the importance of quantum dots, conjugated polymers, carbon nanotubes and photosynthetic light-harvesting antenna complexes.
Journal ArticleDOI
Small-Diameter Silicon Nanowire Surfaces
TL;DR: These hydrogen-terminated SiNW surfaces seem to be more oxidation-resistant than regular silicon wafer surfaces, because atomically resolved STM images of SiNWs were obtained in air after several days' exposure to the ambient environment.
Journal ArticleDOI
Fine structure of neutral and charged excitons in self-assembled In(Ga)As/(Al)GaAs quantum dots
Manfred Bayer,Gerhard E. Ortner,O. Stern,A. Kuther,A. Gorbunov,Alfred Forchel,Pawel Hawrylak,Simon Fafard,Karin Hinzer,T. L. Reinecke,Scott N. Walck,Johann Peter Reithmaier,F. Klopf,F. Schäfer +13 more
TL;DR: In this article, the fine structure of excitons is studied by magnetophotoluminescence spectroscopy of single self-assembled In(Ga)As/(Al)GaAs quantum dots.
Journal ArticleDOI
Size-controlled highly luminescent silicon nanocrystals: A SiO/SiO2 superlattice approach
TL;DR: In this article, the size control of SiO/SiO2 superlattices with an upper limit of the nanocrystal sizes of 3.8, 2.5, and 2.0 nm was investigated.
Journal ArticleDOI
Observation of the "Dark exciton" in CdSe quantum dots.
TL;DR: The band edge exciton structure is calculated, including the effects of the electron-hole exchange interaction and a nonspherical shape, in CdSe quantum dots to show the importance of exciton spin dynamics in the recombination mechanism.