1
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Popelář T, Matějka F, Kopenec J, Morselli G, Ceroni P, Kůsová K. Why do Si quantum dots with stronger fast emission have lower external photoluminescence quantum yield? NANOSCALE ADVANCES 2024; 6:2644-2655. [PMID: 38752139 PMCID: PMC11093259 DOI: 10.1039/d3na01031g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Accepted: 04/08/2024] [Indexed: 05/18/2024]
Abstract
Silicon quantum dots (QDs) are a promising non-toxic alternative to the already well-developed platform of light-emitting semiconductor QDs based on III-V and II-VI materials. Oxidized SiQDs or those surface-terminated with long alkyl chains typically feature long-lived orange-red photoluminescence originating in quantum-confined core states. However, sometimes an additional short-lived PL band, whose mechanism is still highly debated, is reported. Here, we perform a detailed study of the room-temperature PL of SiQDs using samples covering three main fabrication techniques. We find evidence for the presence of only one set of radiative processes in addition to the typical long-lived PL. Moreover, we experimentally determine the ratio between the short- and long-lived PL component, obtaining a wide range of values (0.003 - 0.1) depending on the type of sample. In accordance with an already published report, we observe a tendency of SiQDs with stronger short-lived PL to have lower external quantum yield. We explain this trend using a model of the optical performance of an ensemble of QDs with widely varying optical characteristics through a mechanism we call selective lifetime-based quenching.
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Affiliation(s)
- Tomáš Popelář
- Institute of Physics of the CAS v.v.i., Cukrovarnická 10 162 00 Prague 6 Czechia
| | - Filip Matějka
- Institute of Physics of the CAS v.v.i., Cukrovarnická 10 162 00 Prague 6 Czechia
- University of Chemistry and Technology Technická 5 166 28 Praha 6 Czechia
| | - Jakub Kopenec
- Institute of Physics of the CAS v.v.i., Cukrovarnická 10 162 00 Prague 6 Czechia
| | - Giacomo Morselli
- Chemistry Department "Giacomo Ciamician", University of Bologna Via F. Selmi 2 40126 Bologna Italy
| | - Paola Ceroni
- Chemistry Department "Giacomo Ciamician", University of Bologna Via F. Selmi 2 40126 Bologna Italy
| | - Kateřina Kůsová
- Institute of Physics of the CAS v.v.i., Cukrovarnická 10 162 00 Prague 6 Czechia
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2
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Su Y, Wang C, Hong Z, Sun W. Thermal Disproportionation for the Synthesis of Silicon Nanocrystals and Their Photoluminescent Properties. Front Chem 2021; 9:721454. [PMID: 34458238 PMCID: PMC8397416 DOI: 10.3389/fchem.2021.721454] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Accepted: 07/09/2021] [Indexed: 11/13/2022] Open
Abstract
In the past decades, silicon nanocrystals have received vast attention and have been widely studied owing to not only their advantages including nontoxicity, high availability, and abundance but also their unique luminescent properties distinct from bulk silicon. Among the various synthetic methods of silicon nanocrystals, thermal disproportionation of silicon suboxides (often with H as another major composing element) bears the superiorities of unsophisticated equipment requirements, feasible processing conditions, and precise control of nanocrystals size and structure, which guarantee a bright industrial application prospect. In this paper, we summarize the recent progress of thermal disproportionation chemistry for the synthesis of silicon nanocrystals, with the focus on the effects of temperature, Si/O ratio, and the surface groups on the resulting silicon nanocrystals’ structure and their corresponding photoluminescent properties. Moreover, the paradigmatic application scenarios of the photoluminescent silicon nanocrystals synthesized via this method are showcased or envisioned.
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Affiliation(s)
- Yize Su
- State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou, China
| | - Chenhao Wang
- State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou, China
| | - Zijian Hong
- Lab of Dielectric Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou, China
| | - Wei Sun
- State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou, China
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3
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Coffer JL, Canham LT. Nanoporous Silicon as a Green, High-Tech Educational Tool. NANOMATERIALS 2021; 11:nano11020553. [PMID: 33672198 PMCID: PMC7926729 DOI: 10.3390/nano11020553] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/27/2020] [Revised: 02/13/2021] [Accepted: 02/15/2021] [Indexed: 12/25/2022]
Abstract
Pedagogical tools are needed that link multidisciplinary nanoscience and technology (NST) to multiple state-of-the-art applications, including those requiring new fabrication routes relying on green synthesis. These can both educate and motivate the next generation of entrepreneurial NST scientists to create innovative products whilst protecting the environment and resources. Nanoporous silicon shows promise as such a tool as it can be fabricated from plants and waste materials, but also embodies many key educational concepts and key industrial uses identified for NST. Specific mechanical, thermal, and optical properties become highly tunable through nanoporosity. We also describe exceptional properties for nanostructured silicon like medical biodegradability and efficient light emission that open up new functionality for this semiconductor. Examples of prior lecture courses and potential laboratory projects are provided, based on the author’s experiences in academic chemistry and physics departments in the USA and UK, together with industrial R&D in the medical, food, and consumer-care sectors. Nanoporous silicon-based lessons that engage students in the basics of entrepreneurship can also readily be identified, including idea generation, intellectual property, and clinical translation of nanomaterial products.
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Affiliation(s)
- Jeffery L. Coffer
- Department of Chemistry and Biochemistry, Texas Christian University, Fort Worth, TX 76129, USA
- Correspondence: (J.L.C.); (L.T.C.)
| | - Leigh T. Canham
- School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
- Correspondence: (J.L.C.); (L.T.C.)
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4
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Zhang DX, Esser L, Vasani RB, Thissen H, Voelcker NH. Porous silicon nanomaterials: recent advances in surface engineering for controlled drug-delivery applications. Nanomedicine (Lond) 2020; 14:3213-3230. [PMID: 31855121 DOI: 10.2217/nnm-2019-0167] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Porous silicon (pSi) nanomaterials are increasingly attractive for biomedical applications due to their promising properties such as simple and feasible fabrication procedures, tunable morphology, versatile surface modification routes, biocompatibility and biodegradability. This review focuses on recent advances in surface modification of pSi for controlled drug delivery applications. A range of functionalization strategies and fabrication methods for pSi-polymer hybrids are summarized. Surface engineering solutions such as stimuli-responsive polymer grafting, stealth coatings and active targeting modifications are highlighted as examples to demonstrate what can be achieved. Finally, the current status of engineered pSi nanomaterials for in vivo applications is reviewed and future prospects and challenges in drug-delivery applications are discussed.
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Affiliation(s)
- De-Xiang Zhang
- Drug Delivery, Disposition & Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, 3052, Australia.,Commonwealth Scientific & Industrial Research Organisation (CSIRO), Manufacturing, Clayton, Victoria, 3168, Australia
| | - Lars Esser
- Commonwealth Scientific & Industrial Research Organisation (CSIRO), Manufacturing, Clayton, Victoria, 3168, Australia
| | - Roshan B Vasani
- Drug Delivery, Disposition & Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, 3052, Australia
| | - Helmut Thissen
- Commonwealth Scientific & Industrial Research Organisation (CSIRO), Manufacturing, Clayton, Victoria, 3168, Australia
| | - Nicolas H Voelcker
- Drug Delivery, Disposition & Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, 3052, Australia.,Commonwealth Scientific & Industrial Research Organisation (CSIRO), Manufacturing, Clayton, Victoria, 3168, Australia.,Melbourne Centre for Nanofabrication, Victorian Node of Australian National Fabrication Facility, Clayton, Victoria, 3168, Australia
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5
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Galář P, Popelář T, Khun J, Matulková I, Němec I, Newell KD, Michalcová A, Scholtz V, Kůsová K. The red and blue luminescence in silicon nanocrystals with an oxidized, nitrogen-containing shell. Faraday Discuss 2020; 222:240-257. [PMID: 32104864 DOI: 10.1039/c9fd00092e] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Traditionally, two classes of silicon nanocrystals (SiNCs) are recognized with respect to their light-emission properties. These are usually referred to as the "red" and the "blue" emitting SiNCs, based on the spectral region in which the larger part of their luminescence is concentrated. The origin of the "blue" luminescence is still disputed and is very probably different in different systems. One of the important contributions to the discussion about the origin of the "blue" luminescence was the finding that the exposure of SiNCs to even trace amounts of nitrogen in the presence of oxygen induces the "blue" emission, even in originally "red"-emitting SiNCs. Here, we obtained a different result. We show that the treatment of "red" emitting, already oxidized SiNCs in a water-based environment containing air-related radicals including nitrogen-containing species as well as oxygen, diminishes, rather than induces the "blue" luminescence.
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Affiliation(s)
- Pavel Galář
- Institute of Physics, Czech Academy of Sciences, Cukrovarnická 10, Prague 6, 162 00, Czech Republic.
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6
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Canham L. Introductory lecture: origins and applications of efficient visible photoluminescence from silicon-based nanostructures. Faraday Discuss 2020; 222:10-81. [DOI: 10.1039/d0fd00018c] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
This review highlights many spectroscopy-based studies and selected phenomenological studies of silicon-based nanostructures that provide insight into their likely PL mechanisms, and also covers six application areas.
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Affiliation(s)
- Leigh Canham
- School of Physics and Astronomy
- University of Birmingham
- Birmingham
- UK
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7
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Grulke EA, Beck MJ, Yokel RA, Unrine JM, Graham UM, Hancock ML. Surface-controlled dissolution rates: a case study of nanoceria in carboxylic acid solutions. ENVIRONMENTAL SCIENCE. NANO 2019; 6:1478-1492. [PMID: 31372227 PMCID: PMC6675026 DOI: 10.1039/c9en00222g] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Nanoparticle dissolution in local milieu can affect their ecotoxicity and therapeutic applications. For example, carboxylic acid release from plant roots can solubilize nanoceria in the rhizosphere, affecting cerium uptake in plants. Nanoparticle dispersions were dialyzed against ten carboxylic acid solutions for up to 30 weeks; the membrane passed cerium-ligand complexes but not nanoceria. Dispersion and solution samples were analyzed for cerium by inductively coupled plasma mass spectrometry (ICP-MS). Particle size and shape distributions were measured by transmission electron microscopy (TEM). Nanoceria dissolved in all carboxylic acid solutions, leading to cascades of progressively smaller nanoparticles and producing soluble products. The dissolution rate was proportional to nanoparticle surface area. Values of the apparent dissolution rate coefficients varied with the ligand. Both nanoceria size and shape distributions were altered by the dissolution process. Density functional theory (DFT) estimates for some possible Ce(IV) products showed that their dissolution was thermodynamically favored. However, dissolution rate coefficients did not generally correlate with energy of formation values. The surface-controlled dissolution model provides a quantitative measure for nanoparticle dissolution rates: further studies of dissolution cascades should lead to improved understanding of mechanisms and processes at nanoparticle surfaces.
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Affiliation(s)
- Eric A. Grulke
- Chemical & Materials Engineering, University of
Kentucky
| | - Matthew J. Beck
- Chemical & Materials Engineering, University of
Kentucky
- Center for Computational Sciences, University of
Kentucky
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8
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Koshida N, Nakamura T. Emerging Functions of Nanostructured Porous Silicon-With a Focus on the Emissive Properties of Photons, Electrons, and Ultrasound. Front Chem 2019; 7:273. [PMID: 31069217 PMCID: PMC6491725 DOI: 10.3389/fchem.2019.00273] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Accepted: 04/02/2019] [Indexed: 11/13/2022] Open
Abstract
Recent topics of application studies on porous silicon (PS) are reviewed here with a focus on the emissive properties of visible light, quasiballistic hot electrons, and acoustic wave. By exposing PS in solvents to pulse laser, size-controlled nc-Si dot colloids can be formed through fragmentation of the PS layer with a considerably higher yield than the conventional techniques such as laser ablation of bulk silicon and sol-gel precursor process. Fabricated colloidal samples show strong visible photoluminescence (~40% in quantum efficiency in the red band). This provides an energy- and cost-effective route for production of nc-Si quantum dots. A multiple-tunneling transport mode through nc-Si dot chain induces efficient quasiballistic hot electron emission from an nc-Si diode. Both the efficiency and the output electron energy dispersion are remarkably improved by using monolayer graphene as a surface electrode. Being a relatively low operating voltage device compatible with silicon planar fabrication process, the emitter is applicable to mask-less parallel lithography under an active matrix drive. It has been demonstrated that the integrated 100 × 100 emitter array is useful for multibeam lithography and that the selected emission pattern is delineated with little distortion. Highly reducing activity of emitted electrons is applicable to liquid-phase thin film deposition of metals (Cu) and semiconductors (Si, Ge, and SiGe). Due to an extremely low thermal conductivity and volumetric heat capacity of nc-Si layer, on the other hand, thermo-acoustic conversion is enhanced to a practical level. A temperature fluctuation produced at the surface of nc-Si layer is quickly transferred into air, and then an acoustic wave is emitted without any mechanical vibrations. The non-resonant and broad-band emissivity with low harmonic distortions makes it possible to use the emitter for generating audible sound under a full digital drive and reproducing complicated ultrasonic communication calls between mice.
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Affiliation(s)
- Nobuyoshi Koshida
- Graduate School of Engineering, Tokyo University of Agriculture and Technology, Fuchu, Japan
| | - Toshihiro Nakamura
- Department of Electrical and Electronic Engineering, Hosei University, Tokyo, Japan
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9
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Dasog M, Kehrle J, Rieger B, Veinot JGC. Silicon Nanocrystals and Silicon-Polymer Hybrids: Synthesis, Surface Engineering, and Applications. Angew Chem Int Ed Engl 2015; 55:2322-39. [DOI: 10.1002/anie.201506065] [Citation(s) in RCA: 195] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Revised: 09/18/2015] [Indexed: 12/16/2022]
Affiliation(s)
- Mita Dasog
- Division of Chemistry and Chemical Engineering; California Institute of Technology; 1200 East California Boulevard Pasadena CA 91125 USA
| | - Julian Kehrle
- WACKER-Lehrstuhl für Makromolekulare Chemie; Technische Universität München; Lichtenbergstrasse 4 85747 Garching Germany
| | - Bernhard Rieger
- WACKER-Lehrstuhl für Makromolekulare Chemie; Technische Universität München; Lichtenbergstrasse 4 85747 Garching Germany
| | - Jonathan G. C. Veinot
- Department of Chemistry; University of Alberta; 11227 Saskatchewan Drive Edmonton Alberta T6G 2G2 Canada
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10
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Dasog M, Kehrle J, Rieger B, Veinot JGC. Silicium-Nanokristalle und Silicium-Polymer-Hybridmaterialien: Synthese, Oberflächenmodifikation und Anwendungen. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201506065] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Mita Dasog
- Division of Chemistry and Chemical Engineering; California Institute of Technology; 1200 East California Boulevard Pasadena CA 91125 USA
| | - Julian Kehrle
- WACKER-Lehrstuhl für Makromolekulare Chemie; Technische Universität München; Lichtenbergstraße 4 85747 Garching Deutschland
| | - Bernhard Rieger
- WACKER-Lehrstuhl für Makromolekulare Chemie; Technische Universität München; Lichtenbergstraße 4 85747 Garching Deutschland
| | - Jonathan G. C. Veinot
- Department of Chemistry; University of Alberta; 11227 Saskatchewan Drive Edmonton Alberta T6G 2G2 Kanada
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11
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Hwang J, Jeong Y, Lee KH, Seo Y, Kim J, Hong JW, Kamaloo E, Camesano TA, Choi J. Simple Preparation of Fluorescent Silicon Nanoparticles from Used Si Wafers. Ind Eng Chem Res 2015. [DOI: 10.1021/acs.iecr.5b00446] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Jangsun Hwang
- Department
of Bionano Technology, Graduate School, Hanyang University, Seoul 133-791, Korea
| | - Yoon Jeong
- Department
of Bionano Technology, Graduate School, Hanyang University, Seoul 133-791, Korea
- Department
of Bionano Engineering, Hanyang University ERICA, Ansan, Gyeonggi 426-791, Korea
| | - Kwan Hong Lee
- Department
of Bionano Technology, Graduate School, Hanyang University, Seoul 133-791, Korea
- Department
of Bionano Engineering, Hanyang University ERICA, Ansan, Gyeonggi 426-791, Korea
- OpenView Venture
Partners, Boston, Massachusetts 02210, United States
| | - Youngmin Seo
- Department
of Bionano Technology, Graduate School, Hanyang University, Seoul 133-791, Korea
| | - Jieun Kim
- Department
of Bionano Technology, Graduate School, Hanyang University, Seoul 133-791, Korea
| | - Jong Wook Hong
- Department
of Bionano Technology, Graduate School, Hanyang University, Seoul 133-791, Korea
- Department
of Bionano Engineering, Hanyang University ERICA, Ansan, Gyeonggi 426-791, Korea
| | - Elaheh Kamaloo
- Department
of Chemical Engineering, Worcester Polytechnic Institute, Worcester, Massachusetts 01609, United States
| | - Terri A. Camesano
- Department
of Chemical Engineering, Worcester Polytechnic Institute, Worcester, Massachusetts 01609, United States
| | - Jonghoon Choi
- Department
of Bionano Technology, Graduate School, Hanyang University, Seoul 133-791, Korea
- Department
of Bionano Engineering, Hanyang University ERICA, Ansan, Gyeonggi 426-791, Korea
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12
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Xia B, Wang B, Shi J, Zhang W, Xiao SJ. Engineering near-infrared fluorescent styrene-terminated porous silicon nanocomposites with bovine serum albumin encapsulation for in vivo imaging. J Mater Chem B 2014; 2:8314-8320. [DOI: 10.1039/c4tb01209g] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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13
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Dohnalová K, Gregorkiewicz T, Kůsová K. Silicon quantum dots: surface matters. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2014; 26:173201. [PMID: 24713583 DOI: 10.1088/0953-8984/26/17/173201] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Silicon quantum dots (SiQDs) hold great promise for many future technologies. Silicon is already at the core of photovoltaics and microelectronics, and SiQDs are capable of efficient light emission and amplification. This is crucial for the development of the next technological frontiers-silicon photonics and optoelectronics. Unlike any other quantum dots (QDs), SiQDs are made of non-toxic and abundant material, offering one of the spectrally broadest emission tunabilities accessible with semiconductor QDs and allowing for tailored radiative rates over many orders of magnitude. This extraordinary flexibility of optical properties is achieved via a combination of the spatial confinement of carriers and the strong influence of surface chemistry. The complex physics of this material, which is still being unraveled, leads to new effects, opening up new opportunities for applications. In this review we summarize the latest progress in this fascinating research field, with special attention given to surface-induced effects, such as the emergence of direct bandgap transitions, and collective effects in densely packed QDs, such as space separated quantum cutting.
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Affiliation(s)
- K Dohnalová
- Van der Waals-Zeeman Institute, University of Amsterdam, Science Park 904, NL-1098 XH Amsterdam, The Netherlands
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14
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Nontapot K, Rastogi V, Fagan JA, Reipa V. Size and density measurement of core-shell Si nanoparticles by analytical ultracentrifugation. NANOTECHNOLOGY 2013; 24:155701. [PMID: 23518716 DOI: 10.1088/0957-4484/24/15/155701] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Si nanocrystals, terminated with cyclohexane and allylamine, were analyzed using analytical ultracentrifugation (AUC), dynamic light scattering (DLS) and transmission electron microscopy. We found that AUC yielded equivalent particle size distribution data to other nanoparticle characterization techniques, while also providing important information not probed by techniques such as DLS regarding the relative size of the particle core and shell components and the overall effective particle density. Estimates of particle core and shell dimensions are consistent with the particle's optical properties within the quantum confinement representation and available theoretical Si nanocrystal models. Measurement of sedimentation velocity in several solvents with different densities presents a way to circumvent the ambiguity of simultaneous fitting of particle density and sedimentation coefficient and allows us to significantly reduce the uncertainty in the estimates of particle hydrodynamic diameter by finding the effective particle density value.
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Affiliation(s)
- Kanokwan Nontapot
- Biochemical Sciences Division, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
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15
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Long YM, Zhao QL, Zhang ZL, Tian ZQ, Pang DW. Electrochemical methods – important means for fabrication of fluorescent nanoparticles. Analyst 2012; 137:805-15. [DOI: 10.1039/c2an15740c] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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16
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Reipa V, Purdum G, Choi J. Measurement of nanoparticle concentration using quartz crystal microgravimetry. J Phys Chem B 2010; 114:16112-7. [PMID: 20961086 DOI: 10.1021/jp103861m] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Various nanoscale items (e.g., nanoparticles and nanotubes) have been actively investigated due to their unique physicochemical properties. A common issue encountered in such studies is accurate expression of nanoparticle concentration. Given the critical importance of the dose-response relationship, we present the use of quartz crystal microgravimetry (QCM) to accurately measure nanoparticle concentration in a colloidal suspension. Application of a small drop of the nanoparticle suspension in a volatile solvent to the crystal surface leaves a dry nanoparticle residue after solvent evaporation after which the shift in the crystal resonant frequency is recorded. The instrument was calibrated using a set of serial dilutions of Si and Ag nanopowder in methanol, rhodamine B in methanol, and ferrocene in cyclohexane. Using QCM, a linear response for nanoparticle concentrations up to 1300 μg/mL was determined. The developed method was used to determine the concentrations of size-selected, octyl-terminated Si nanocrystal samples with median diameters in the range 1.1-14.8 nm and also to calculate size-dependent nanocrystal extinction coefficients.
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Affiliation(s)
- Vytas Reipa
- Biochemical Science Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
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17
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Abstract
Neurons in vitro are different from any other cell types in their sensitivity and complexity. Growing, differentiating, transfecting, and recording from single neurons and neuronal networks all present particular challenges. Some of the difficulties arise from the small scale of cellular structures, and have already seen substantial advances due to nanotechnology, particularly highly fluorescent semiconductor nanoparticles. Other issues have less obvious solutions, but the complex and often surprising way that novel nanomaterials react with cells have suggested some revolutionary approaches. We review some of the ways nanomaterials and nanostructures can contribute to in vitro neuroscience, with a particular focus on emphasizing techniques that are widely accessible to many laboratories and on providing references to protocols and methods. The issues of nanotoxicology of greatest interest to cultured neurons are discussed. Finally, we present some future trends and challenges in nano-neuroscience.
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Affiliation(s)
- Daniel R Cooper
- Department of Biomedical Engineering, McGill University, 3775 Rue University, Montreal, QC H3A 2B4 Canada.
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18
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Portolés MJL, Nieto FR, Soria DB, Amalvy JI, Peruzzo PJ, Mártire DO, Kotler M, Holub O, Gonzalez MC. Photophysical properties of blue - emitting silicon nanoparticles. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2009; 113:13694-13702. [PMID: 22866180 PMCID: PMC3410643 DOI: 10.1021/jp903727n] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Silicon nanoparticles with strong blue photoluminescence were synthesized by electrochemical etching of silicon wafers and ultrasonically removed under N(2) atmosphere in organic solvents to produce colloids. Thermal treatment leads to the formation of colloidal Si particles of 3 ± 1 nm diameter, which upon excitation with 340 - 380 nm light exhibited room temperature luminescence in the range from 400 to 500 nm. The emission and the one- and two-photon excitation spectra of the particles are not sensitive to surface functionalization with methyl 2-methylprop-2-enoate. However, the derivatized particles show higher emission quantum yields in air-saturated suspensions (44%) than the underivatized particles (27%), as well as higher stability of its dispersions.FTIR and XPS spectra indicate a significant surface oxidation of the particles. The Si:O:C ratio at the surface of the derivatized particles estimated from XPS is Si(3)O(6)(C(5)O(2)H(y))(1), with y = 7 - 8. Vibronic spacing is observed in both the emission and excitation spectra. The information obtained from one-photon excitation experiments (emission and excitation spectra, photoluminescence quantum yields, luminescence decay lifetimes and anisotropy correlation lifetimes), as well as from two-photon excitation fluorescence correlation spectroscopy (brightness and diffusion coefficients) and TEM indicate that the blue-emitting particles are monodisperse and ball-shaped. Particle size clearly determines the emission and excitation spectral region, as expected from quantum confinement, but the presence and extent of Si-O species on the silicon networks seem crucial for determining the spectrum features and intensity of emission. The nanoparticles could hold great potential as quantum dots for applications as luminescence sensors in biology and environmental science.
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Affiliation(s)
| | | | - Delia B. Soria
- CEQUINOR, CEQUINOR, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, CC 962, 1900-La Plata, Argentina
| | - Javier I. Amalvy
- INIFTA, Departamento de Química, Facultad de Ciencias Exactas UNLP
| | - Pablo J. Peruzzo
- INIFTA, Departamento de Química, Facultad de Ciencias Exactas UNLP
| | | | - Mónica Kotler
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Argentina
| | - Oliver Holub
- Laboratory for Fluorescence Dynamics, Department of Biomedical Engineering, 3206 Natural Sciences II Bldg., University of California, Irvine (UCI). Irvine, CA 92697-2715, USA
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Choi J, Zhang Q, Reipa V, Wang NS, Stratmeyer ME, Hitchins VM, Goering PL. Comparison of cytotoxic and inflammatory responses of photoluminescent silicon nanoparticles with silicon micron-sized particles in RAW 264.7 macrophages. J Appl Toxicol 2009; 29:52-60. [DOI: 10.1002/jat.1382] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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Shirahata N, Linford MR, Furumi S, Pei L, Sakka Y, Gates RJ, Asplund MC. Laser-derived one-pot synthesis of silicon nanocrystals terminated with organic monolayers. Chem Commun (Camb) 2009:4684-6. [DOI: 10.1039/b905777c] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Stroyuk AL, Shvalagin VV, Raevskaya AE, Kryukov AI, Kuchmii SY. Photochemical formation of semiconducting nanostructures. THEOR EXP CHEM+ 2008. [DOI: 10.1007/s11237-008-9037-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Choi J, Tung SH, Wang NS, Reipa V. Small-angle neutron scattering measurement of silicon nanoparticle size. NANOTECHNOLOGY 2008; 19:085715. [PMID: 21730746 DOI: 10.1088/0957-4484/19/8/085715] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We have determined the particle size distribution profiles of octane-terminated silicon nanoparticle suspensions, produced using the sonication of electrochemically etched Si wafers. Small-angle neutron scattering data was analyzed separately in high (0.4 nm(-1)<q<3.0 nm(-1)) and low (q<0.4 nm(-1)) scattering vector ranges. Data in the high q range is consistent with the log-normal distribution of isolated spherical particles with median diameter d = 3 ± 0.2 nm. Particle sizes were also indirectly assessed from photoluminescence and optical transmission spectroscopy using the size/bandgap relation: E(g) = 3.44d(-0.5), where E(g) is in eV and d in nm. Both measurements were consistent with the particle size distribution profiles, estimated from ANS data fitting and TEM image analysis. A subpopulation of larger, irregular shape structures in the size range 10-50 nm was also indicated by neutron scattering in the low q range and HRTEM images. However, further studies are warranted to explain a relationship between the slope of scattering intensity versus scattering vector dependence in the intermediate scattering vector range (0.4 nm(-1)<q<1.0 nm(-1)) and the role of non-geometrical Si nanoparticle characteristics (mutual interaction forces, surface termination, etc).
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Affiliation(s)
- Jonghoon Choi
- Department of Chemical and Biomolecular Engineering, University of Maryland, College Park, MD 20742, USA. Biochemical Science Division, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
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Choi J, Wang NS, Reipa V. Conjugation of the photoluminescent silicon nanoparticles to streptavidin. Bioconjug Chem 2008; 19:680-5. [PMID: 18290602 DOI: 10.1021/bc700373y] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We have covalently attached multiple photoluminescent silicon nanoparticles (SNs) to streptavidin molecules. Conjugation of SNs to a target protein is achieved using the multistage photoassisted procedure. In a first step, the terminal hydrogen in the freshly prepared SNs is substituted with an alkane monolayer that serves as a platform for chemical linkage to a heterobifunctional cross-linker: 4-azido-2,3,5,6-tetrafluorobenzoic acid, succinimidyl ester. A resulting surface coating stabilizes nanoparticles against oxidation and aggregation. Next, an open end of bifunctional cross-linker-diazirine succinimidyl ester is reacted with carboxyl moieties of streptavidin and forms an amide bond. Gel and capillary electrophoresis of the SN-streptavidin complex demonstrated separate elution of the conjugation product and unreacted protein. Then, the number of SNs per protein molecule was determined by measuring complex charge variation by capillary electrophoresis. Conjugate functionality was tested by allowing it to interact with biotinylated polystyrene microbeads. Intense photoluminescence at carefully washed microbeads demonstrated selective binding of silicon nanoparticle bearing streptavidin to biotinylated microbeads. The high quantum yield of streptavidin-SN conjugate in combination with the small size and biocompatibility of silicon nanoparticles presents an attractive platform for the fluorescence labeling in diverse bioassays.
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Affiliation(s)
- Jonghoon Choi
- Department of Chemical and Biomolecular Engineering, University of Maryland, College Park, MD 20742, USA
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