Hot-phonon-induced indirect absorption in silicon nanocrystals

Kozák, Martin; Kořínek, M.; Trojánek, F.; Hiller, Daniel; Gutsch, Sebastian; Zacharias, Margit; Malý, P.

doi:10.1063/1.4829006

Cited by 4 publications

(2 citation statements)

References 24 publications

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“…The transient transmission signals are positive indicating an induced absorption as is expected 19 . There is a very small probability of indirect absorption of 800 nm (1.55 eV) photons by valence band-conduction band transition from Γ point to X valleys 20 and intra-band excited carrier absorption (by previously excited electrons in X valleys and holes) dominates. The absorption at 800 nm is thus supposed to be proportional to the density of photoexcited carriers 21 .…”

Section: Resultsmentioning

confidence: 99%

Interplay of bimolecular and Auger recombination in photoexcited carrier dynamics in silicon nanocrystal/silicon dioxide superlattices

Chlouba

Trojánek

Laube

et al. 2018

Sci Rep

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We report results of investigating carrier recombination in silicon nanocrystal/silicon dioxide superlattices. The superlattices prepared by nitrogen-free plasma enhanced chemical vapour deposition contained layers of silicon nanocrystals. Femtosecond transient transmission optical spectroscopy was used to monitor carrier mechanisms in the samples. The three-particle Auger recombination was observed in accord with previous reports. However, under high pump intensities (high photoexcited carrier densities) the bimolecular process dominated the recombination. Detailed analysis of measured data and fitting procedure made it possible to follow and quantify the interplay between the two recombination processes. The bimolecular recombination was interpreted in terms of the trap-assisted Auger recombination.

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Section: Resultsmentioning

confidence: 99%

Interplay of bimolecular and Auger recombination in photoexcited carrier dynamics in silicon nanocrystal/silicon dioxide superlattices

Chlouba

Trojánek

Laube

et al. 2018

Sci Rep

Self Cite

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“…The pump flux is chosen to generate only a few excitons per NC [ 45 ]. Specifically, 2.3 mJ/cm 2 (SRON) and 3.4 mJ/cm 2 (SRO) were used, which correspond to the excitation regime with normal Auger recombination of excitons, excluding bimolecular recombination [ 46 ].…”

Section: Resultsmentioning

confidence: 99%

Absence of free carriers in silicon nanocrystals grown from phosphorus- and boron-doped silicon-rich oxide and oxynitride

Hiller¹,

López-Vidrier²,

Nomoto³

et al. 2018

Beilstein J. Nanotechnol.

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Phosphorus- and boron-doped silicon nanocrystals (Si NCs) embedded in silicon oxide matrix can be fabricated by plasma-enhanced chemical vapour deposition (PECVD). Conventionally, SiH4 and N2O are used as precursor gasses, which inevitably leads to the incorporation of ≈10 atom % nitrogen, rendering the matrix a silicon oxynitride. Alternatively, SiH4 and O2 can be used, which allows for completely N-free silicon oxide. In this work, we investigate the properties of B- and P-incorporating Si NCs embedded in pure silicon oxide compared to silicon oxynitride by atom probe tomography (APT), low-temperature photoluminescence (PL), transient transmission (TT), and current–voltage (I–V) measurements. The results clearly show that no free carriers, neither from P- nor from B-doping, exist in the Si NCs, although in some configurations charge carriers can be generated by electric field ionization. The absence of free carriers in Si NCs ≤5 nm in diameter despite the presence of P- or B-atoms has severe implications for future applications of conventional impurity doping of Si in sub-10 nm technology nodes.

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Picosecond dynamics of photoexcited carriers in silicon nanocrystal/Si3N4 superlattices: Presence of K centers

Kořínek

Trojánek

Hiller

et al. 2015

Journal of Applied Physics

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We report in detail on the picosecond dynamics of photoexcited charge carriers in size-controlled silicon nanocrystals in silicon nanocrystal/Si3N4 superlattices. The samples were prepared using plasma enhanced chemical vapor deposition and subsequent thermally induced phase separation. The pump and probe transmission technique was used to monitor directly the initial (picosecond) carrier dynamics. The transient transmission signal (decay time about 2 ps) was found to be independent of the nanocrystal size, pump pulse intensity and wavelength from the interval 400 to 700 nm. The signal is attributed to the dynamics of photoexcited carriers captured on the K0 centers in Si3N4.

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Hot-phonon-induced indirect absorption in silicon nanocrystals

Cited by 4 publications

References 24 publications

Interplay of bimolecular and Auger recombination in photoexcited carrier dynamics in silicon nanocrystal/silicon dioxide superlattices

Interplay of bimolecular and Auger recombination in photoexcited carrier dynamics in silicon nanocrystal/silicon dioxide superlattices

Absence of free carriers in silicon nanocrystals grown from phosphorus- and boron-doped silicon-rich oxide and oxynitride

Picosecond dynamics of photoexcited carriers in silicon nanocrystal/Si3N4 superlattices: Presence of K centers

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