On the origin of the fast photoluminescence band in small silicon nanoparticles

Valenta, J.; Fučíková, Anna; Pelant, I.; Kůsová, Kateřina; Dohnalová, Kateřina; Aleknavičius, Aidas; Cibulka, Ondřej; Fojtík, A.; Kada, Gerald

doi:10.1088/1367-2630/10/7/073022

Cited by 85 publications

(57 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…6 and 7 for reviews). Recent observations of a very efficient blue emission from excited Si NCs on ultrafast time scale and of other short-living emission bands 5,[8][9][10] call for a systematic description of the relaxation processes following the excitation of the non-equilibrium charge carriers in Si NCs. Excitation by light with the photon energy exceeding the optical gap of Si NCs creates mainly hot electrons and cold holes.…”

mentioning

confidence: 99%

Multiphonon relaxation of moderately excited carriers in Si/SiO2nanocrystals

et al. 2012

View full text Add to dashboard Cite

We study the phonon-assisted intraband relaxation of electrons and holes confined in Si nanocrystals. The rates of relaxation processes are calculated as functions of the nanocrystal size and of the temperature. It occurs that the main contribution to the relaxation is provided by the mechanism where a single acoustic and a number of optical phonons, which is necessary to compensate the energy difference between the quantized charge carrier levels, are involved. We show that the phonon-assisted transitions between neighboring, size-quantized levels occur typically on a picosecond timescale, but vary over several orders of magnitude with the nanocrystal size. This results in a multi-exponential decay of the carrier populations averaged over an ensemble of the nanocrystals with a given size distribution. When the nanocrystal size is reduced and more than two phonons are required for the transition, there is a qualitative difference in the behavior of the transition probabilities between the electrons and the holes. Whereas the electron transition times strongly oscillate around approximately the same mean values in the picosecond range with some drops towards nanoseconds, there is a clearly pronounced tendency of the relaxation time increase into the nanosecond time range for the hole transitions when the nanocrystal size is decreased. The increase of the temperature leads to a moderate decrease of the relaxation times but does not change the picture qualitatively.

show abstract

mentioning

confidence: 99%

Multiphonon relaxation of moderately excited carriers in Si/SiO2nanocrystals

et al. 2012

View full text Add to dashboard Cite

show abstract

“…A number of mechanisms and recombination processes have been proposed, pursuing five main concepts: recombination of the photoexcited carriers confined within the c-Si core of Si NCs [1,2], reconstruction of the states in very small Si NCs (inner or surface Si-Si bond) [3,4], Si-based molecules (Si clusters with different morphology, polysilane) [5][6][7], point defects in SiO 2 [8,9] or direct transition at the Γ -point [10]. A border between the mechanisms is sometimes questionable.…”

mentioning

confidence: 99%

Ultrafast photoluminescence dynamics of blue‐emitting silicon nanostructures

Žídek

Trojánek

Malý

et al. 2011

Phys. Status Solidi (c)

View full text Add to dashboard Cite

show abstract

“…The F band luminescence, usually centered between 420 and 500 nm, decays on the nanosecond time scale. This can be observed on porous silicon samples aged in air or intentionally oxidized, and is thought to originate from structural defects in the silicon nanocrystal oxide shell, or from the luminescence of very small silicon nanocrystals [19,39,[69][70][71][72]. Other PL bands have been previously reported for porous silicon: the so-called UV band (centered around 350 nm), and the R band (ranging from 1100-1500 nm) [59].…”

Section: Optical Characterizationmentioning

confidence: 85%