Experimental Evidence for the Quantum Confinement Effect in 3<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>C</mml:mi></mml:math>-SiC Nanocrystallites

Wu, Xiaowei; Fan, Jiyang; Qiu, Teng; Yang, Xingming; Siu, G. G.; Chu, Paul K.

doi:10.1103/physrevlett.94.026102

Cited by 304 publications

(183 citation statements)

References 30 publications

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“…15 Additionally, it has been previously shown by FTIR analysis that SiC x O y films contain Si-C bonds, whose density increases with C concentration. 7 The stoichiometry trend of SiC x O y suggests that two divalent oxygen atoms are replaced by one tetravalent C (SiC x O 2(1Àx) ), offering additional support for the presence of the ( Si-) 3 C • radicals in our films, as they may originate from oxygen incorporation in ( Si-) 4 C structures. Consequently, the density of such radicals is expected to increase following thermal oxidation of ( Si-) 4Àn CH n groups, which have not been completely dehydrated during the film deposition.…”

Section: (B)mentioning

confidence: 99%

“…To this end, an extensively explored prior research direction was based on quantum confinement effects of Si or SiC nanocrystals to enable strong light emission. 4 Since the emission wavelengths of nanocrystals strongly depend on their size, it was necessary to grow nanocrystals with three distinct size distributions-corresponding to the red, green, and blue emissions-within the same crystal matrix, in order to achieve white luminescence. In practice, this task was very difficult to realize due to the nanocrystal size distribution being dictated by the growth conditions.…”

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confidence: 99%

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The origin of white luminescence from silicon oxycarbide thin films

Nikas¹,

Gallis²,

Huang³

et al. 2014

Applied Physics Letters

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Silicon oxycarbide (SiCxOy) is a promising material for achieving strong room-temperature white luminescence. The present work investigated the mechanisms for light emission in the visible/ultraviolet range (1.5–4.0 eV) from chemical vapor deposited amorphous SiCxOythin films, using a combination of optical characterizations and electron paramagnetic resonance(EPR) measurements. Photoluminescence(PL) and EPR studies of samples, with and without post-deposition passivation in an oxygen and forming gas (H2 5 at. % and N2 95 at. %) ambient, ruled out typical structural defects in oxides, e.g., Si-related neutral oxygen vacancies or non-bridging oxygen hole centers, as the dominant mechanism for white luminescence from SiCxOy. The observed intense white luminescence (red, green, and blue emission) is believed to arise from the generation of photo-carriers by optical absorption through C-Si-O related electronic transitions,and the recombination of such carriers between bands and/or at band tail states. This assertion is based on the realization that the PL intensity dramatically increased at an excitation energy coinciding with the E04 band gaps of the material, as well as by the observed correlation between the Si-O-C bond density and the PLintensity. An additional mechanism for the existence of a blue component of the white emission is also discussed.

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Section: (B)mentioning

confidence: 99%

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confidence: 99%

The origin of white luminescence from silicon oxycarbide thin films

Nikas¹,

Gallis²,

Huang³

et al. 2014

Applied Physics Letters

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“…The most common PL origin due to subgap emission is radiative recombination of defects and surface states [52], while above-gap emission is attributed to quantum confinement phenomenon in small nanocrystals such as quantum dots (QDs). At present the peak emission wavelengths of the SiC QDs are in the UV-blue-green region, typically between 380 nm and 550 nm [53][54][55][56]. This spectral emission region, however, is not ideal for biomedical applications due to the cell autofluorescence in the same spectral band.…”

Section: Single-photon Sources In Nanomaterialsmentioning

confidence: 99%

Silicon Carbide for Novel Quantum Technology Devices

Castelletto¹,

Rosa²,

Johnson³

2015

Advanced Silicon Carbide Devices and Processing

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Silicon carbide (SiC) has recently been investigated as an alternative material to host deep optically active defects suitable for optical and spin quantum bits. This material presents a unique opportunity to realise more advanced quantum-based devices and sensors than currently possible. We will summarise key results revealing the role that defects have played in enabling optical and spin quantum measurements in this material such as single photon emission and optical spin control. The great advantage of SiC lies in its existing and well-developed device processing protocols and the possibilities to integrate these defects in a straightforward manner. There is particular current interest in nanomaterials and nanophotonics in SiC that could, once realised, introduce a new platform for quantum nanophotonics and in general for photonics. We will summarise SiC nanostructures exhibiting optical emission due to multiple polytypic bandgap engineering and deep defects. The combination of nanostructures and in-built paramagnetic defects in SiC could pave the way for future single-particle and single-defect quantum devices and related biomedical sensors with single-molecule sensitivity. We will review relevant classical devices in SiC (photonics crystal cavities, microdiscs) integrated with intrinsic defects. Finally, we will provide an outlook on future sensors that could arise from the integration of paramagnetic defects in SiC nanostructures and devices.Keywords: Silicon carbide deep defects, Paramagnetic properties, Optical-detected magnetic resonance, Single-photon sources IntroductionThe most common and technologically advanced SiC polytypes are 4H-SiC and 6H-SiC with hexagonal structures and 3C-SiC with a zinc-blende crystal structure (cubic). High-quality © 2015 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.bulk single-crystal 3C-SiC can be grown epitaxially on different substrates, most notably on silicon. This has led to many exciting devices fabricated with this particular polytype [1]. SiC has a wide bandgap (2.4-3.2 eV depending on the polytype), a high thermal conductivity, the ability to sustain high electric fields before breakdown and the highest maximum current density, making it ideal for high-power electronics [2]. More recently, it has become a notable material in the field of quantum computing and spintronics as several of its intrinsic defects are associated with an electron spin that can be used as quantum bit [3,4]. To enhance solid-state quantum systems scalability, a fully integrated device with quantum control should be built; thus, quantum systems should be part of the material used to fabricate the final device. Other solid-state quantum systems fully integrated into a functional device [5][6][7] operate at cryogenic temperatures (4 K or below),...

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“…SiC QDs were successfully fabricated in many ways. [9][10][11][12] The typical diameter is often less than 5 nm. Small size is also of great importance in living cell applications for clearance.…”

Section: Introductionmentioning

confidence: 99%

Silicon carbide quantum dots for bioimaging

et al. 2012

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Luminescent nanocrystals or quantum dots (QDs) have great potential for bioanalysis as well as optoelectronics. Here we report an effective and inexpensive fabrication method of silicon carbide quantum dots (SiC QDs), with diameter below 8 nm, based on electroless wet chemical etching. Our samples show strong violet-blue emission in the 410-450 nm region depending on the solvents used and particle size. The cytotoxic properties of the SiC QDs based on alamarBlue TM assay cells were studied. The presence of the QDs dots does not affect cell growth in a wide concentration range. Two-photon excitation showed significant response from SiC nanocrystals that were injected into hippocampal CA1 pyramidal cells.

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Experimental Evidence for the Quantum Confinement Effect in 3C-SiC Nanocrystallites

Cited by 304 publications

References 30 publications

The origin of white luminescence from silicon oxycarbide thin films

The origin of white luminescence from silicon oxycarbide thin films

Silicon Carbide for Novel Quantum Technology Devices

Silicon carbide quantum dots for bioimaging

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