Highly photoluminescent and stable silicon nanocrystals functionalized <i>via</i> microwave-assisted hydrosilylation

Beri, Deski; Busko, Dmitry; Мазилкин, А. А.; Howard, Ian A.; Richards, Bryce S.; Turshatov, Andrey

doi:10.1039/c7ra13577g

Cited by 8 publications

(22 citation statements)

References 31 publications

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“…A lifetime of ∼125 µs at ∼825 nm was reported for alkylterminated SiNCs with AQY of ∼65% [19]. A lifetime of ∼155 µs at ∼860 nm was reported also for alkyl-terminated SiNCs with maximum AQY of ∼39% [48]. Furthermore, τ ∼65 µs at 800 nm, for PSi having an AQY of 32% (peak wavelength 685 nm) [14].…”

Section: Resultsmentioning

confidence: 82%

Si/SiO2 Core/Shell Luminescent Silicon Nanocrystals and Porous Silicon Powders With High Quantum Yield, Long Lifetime, and Good Stability

et al. 2019

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Most of the highly efficient luminescent silicon nanocrystals (SiNCs) reported to date consist of organically capped silicon cores. Here, we report a method of obtaining Si/SiO 2 core/shell nanoparticles emitting at a peak energy of 1.5 eV with very high quantum yields (53-61%). The same method led to quantum yields of ∼30% for porous silicon powder emitting at 1.9 eV. The SiNCs were very stable under continuous excitation for several hours. The lifetime at 1.5 eV was over 232 µs, the longest ever reported for SiNCs, consistent with the very high luminescence efficiency. The SiNCs were first fabricated by non-thermal plasma synthesis or anodization in the case of porous silicon. Then, a thin oxide shell (∼1 nm) was grown using high-pressure water vapor annealing. This oxidation process allows for the growth of very good quality oxide with low defect concentration and low stress, resulting in very good surface passivation, which explains the very high quantum yields obtained.

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Section: Resultsmentioning

confidence: 82%

Si/SiO2 Core/Shell Luminescent Silicon Nanocrystals and Porous Silicon Powders With High Quantum Yield, Long Lifetime, and Good Stability

et al. 2019

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“…where N em and N abs is number of emitted and absorbed photons respectively, was measured using method described by de Mello et al 35,50,51 In detail, the LED beam was focused by a lens and directed into an integrating sphere (Labsphere) with a diameter of 15 cm. An optical fiber with a diameter of 1 mm (FP1000URT, Thorlabs) was used to collect the emission from integrating sphere and transfer it to the spectrometer (AvaSpec-ULS2048x64TEC, Avantes).…”

Section: Synthetic Methodsmentioning

confidence: 99%

“…34 In our previous work, we have demonstrated that microwave-assisted hydrosilylation (MAH) method can produce SiNc exhibiting a PLQY of up to 40% and excellent long-term stability (6 months without decrease of PLQY). 35 In this article, we describe an approach to attach functional dyes to the core of SiNc via hydrosilylation reaction using a microwave (MW) reactor. As a result, we observed significant enhancement of SiNc NIR PL upon excitation with blue and green light.…”

Section: Introductionmentioning

confidence: 99%

Improved photon absorption in dye-functionalized silicon nanocrystals synthesizedviamicrowave-assisted hydrosilylation

et al. 2020

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“…During this annealing process, the nucleation of SiNCs seeds inside a silicon dioxide matrix occurs (Hessel et al, 2012 ). Details regarding the annealing procedure can be found in the literature (Beri et al, 2018 ). After annealing, the sample was transferred to an agate mortar and ground.…”

Section: Methodsmentioning

confidence: 99%

Enhancing Singlet Oxygen Generation in Conjugates of Silicon Nanocrystals and Organic Photosensitizers

et al. 2020

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Silicon nanocrystals (SiNCs) are regarded as a green and environmentally friendly material when compared with other semiconductor nanocrystals. Ultra-small SiNCs (with the size 4.6-5.2 nm) demonstrate strong UV absorption and photoluminescence in the near infrared (NIR) range with the high photoluminescence quantum yield (PLQY) up to 60%. In contrast to nanoporous silicon, ultra-small SiNCs do not possess an intrinsic ability to generate singlet oxygen (1 O 2). However, we demonstrate that SiNC-dye conjugates synthesized via microwave assistant hydrosilylation reaction produce 1 O 2 with moderate quantum yield () up to 27% in cyclohexane. These interesting results were obtained via measurements of singlet oxygen phosphorescence at 1,270 nm. SiNCs play an important role in the production of singlet oxygen as SiNCs harvest UV and blue radiation and transfer absorbed energy to a triplet state of the attached dyes. It increases the population of the triplet states and leads to the enhancement of the singlet oxygen generation. Simultaneously, the SiNC-dye conjugates demonstrate NIR luminescence with the PLQY up to 22%. Thus, the luminescence behavior and photosensitizing properties of the SiNC-dye conjugates can attract interest as a new multifunctional platform in the field of bio-applications.

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Highly photoluminescent and stable silicon nanocrystals functionalized via microwave-assisted hydrosilylation

Abstract: Herein, we report a microwave-assisted hydrosilylation (MWH) reaction for the surface passivation of silicon nanocrystals (Si-NCs) with linear alkenes.

Cited by 8 publications

References 31 publications

Si/SiO2 Core/Shell Luminescent Silicon Nanocrystals and Porous Silicon Powders With High Quantum Yield, Long Lifetime, and Good Stability

Si/SiO2 Core/Shell Luminescent Silicon Nanocrystals and Porous Silicon Powders With High Quantum Yield, Long Lifetime, and Good Stability

Improved photon absorption in dye-functionalized silicon nanocrystals synthesizedviamicrowave-assisted hydrosilylation

Enhancing Singlet Oxygen Generation in Conjugates of Silicon Nanocrystals and Organic Photosensitizers

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