| 51. |
- Gao, Lingfeng, et al.
(author)
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A Facile Approach for Elemental-Doped Carbon Quantum Dots and Their Application for Efficient Photodetectors
- 2021
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In: Small. - : John Wiley & Sons. - 1613-6810 .- 1613-6829. ; 17:52
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Journal article (peer-reviewed)abstract
- The present work demonstrates a facile hydrothermal approach to synthesize lanthanide-doped carbon quantum dots (CQDs) with europium and/or gadolinium elements. Taking the advantage of broadband adsorption in the ultraviolet-visible region, the doped QDs are directly used as building blocks for photo-electrochemical (PEC)-type photodetectors (PDs) and their performance is systematically investigated under various conditions. The europium (Eu) and gadolinium (Gd) co-doped (C:EuGd) QDs exhibit better photo-response than the single-elemental doped ones and also show outstanding long-term stability. According to the apparent response to light from 350 to 400 nm, the C:EuGd QDs are demonstrated to hold great potential for narrow-band PDs. This work highlights the practical applications of lanthanide-doped CQDs for PDs, and the results are beneficial for the development of elemental-doped CQDs in general.
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| 52. |
- Gao, Lingfeng, et al.
(author)
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Ultra-Small 2D PbS Nanoplatelets : Liquid-Phase Exfoliation and Emerging Applications for Photo-Electrochemical Photodetectors
- 2021
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In: Small. - : John Wiley & Sons. - 1613-6810 .- 1613-6829. ; 17:5
-
Journal article (peer-reviewed)abstract
- 2D PbS nanoplatelets (NPLs) form an emerging class of photoactive materials and have been proposed as robust materials for high-performance optoelectronic devices. However, the main drawback of PbS NPLs is the large lateral size, which inhibits their further investigations and practical applications. In this work, ultra-small 2D PbS NPLs with uniform lateral size (11.2 +/- 1.7 nm) and thickness (3.7 +/- 0.9 nm, approximate to 6 layers) have been successfully fabricated by a facile liquid-phase exfoliation approach. Their transient optical response and photo-response behavior are evaluated by femtosecond-resolved transient absorption and photo-electrochemical (PEC) measurements. It is shown that the NPLs-based photodetectors (PDs) exhibit excellent photo-response performance from UV to the visible range, showing extremely high photo-responsivity (27.81 mA W-1) and remarkable detectivity (3.96 x 10(10) Jones), which are figures of merit outperforming currently reported PEC-type PDs. The outstanding properties are further analyzed based on the results of first-principle calculations, including electronic band structure and free energies for the oxygen evolution reaction process. This work highlights promising applications of ultra-small 2D PbS NPLs with the potential for breakthrough developments also in other fields of optoelectronic devices.
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| 53. |
- Garcia Fernandez, Alberto, et al.
(author)
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Experimental and Theoretical Core Level and Valence Band Analysis of Clean Perovskite Single Crystal Surfaces
- 2022
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In: Small. - : Wiley. - 1613-6810 .- 1613-6829. ; 18:13
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Journal article (peer-reviewed)abstract
- A detailed understanding of the surface and interface properties of lead halide perovskites is of interest for several applications, in which these materials may be used. To develop this understanding, the study of clean crystalline surfaces can be an important stepping stone. In this work, the surface properties and electronic structure of two different perovskite single crystal compositions (MAPbI(3) and Cs(x)FA(1-)(x)PbI(3)) are investigated using synchrotron-based soft X-ray photoelectron spectroscopy (PES), molecular dynamics simulations, and density functional theory. The use of synchrotron-based soft X-ray PES enables high surface sensitivity and nondestructive depth-profiling. Core level and valence band spectra of the single crystals are presented. The authors find two carbon 1s contributions at the surface of MAPbI(3) and assign these to MA(+) ions in an MAI-terminated surface and to MA(+) ions below the surface. It is estimated that the surface is predominantly MAI-terminated but up to 30% of the surface can be PbI2-terminated. The results presented here can serve as reference spectra for photoelectron spectroscopy investigations of technologically relevant polycrystalline thin films, and the findings can be utilized to further optimize the design of device interfaces.
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| 54. |
- Gholamrezaie, Fatemeh, et al.
(author)
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Charge Trapping by Self-Assembled Monolayers as the Origin of the Threshold Voltage Shift in Organic Field-Effect Transistors
- 2012
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In: Small. - : Wiley-VCH Verlag. - 1613-6810 .- 1613-6829. ; 8:2, s. 241-245
-
Journal article (peer-reviewed)abstract
- The threshold voltage is an important property of organic field-effect transistors. By applying a self-assembled monolayer (SAM) on the gate dielectric, the value can be tuned. After electrical characterization, the semiconductor is delaminated. The surface potentials of the revealed SAM perfectly agree with the threshold voltages, which demonstrate that the shift is not due to the dipolar contribution, but due to charge trapping by the SAM.
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| 55. |
- Gonzalez-Diaz, J. B., et al.
(author)
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Plasmonic Au/Co/Au nanosandwiches with enhanced magneto-optical activity
- 2008
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In: Small. - : Wiley. - 1613-6810 .- 1613-6829. ; 4:2, s. 202-205
-
Journal article (peer-reviewed)abstract
- A study was conducted to analyzed magneto-optical (MO) activity of thin films prepared by Au/Co/Au trilayers as surface plasmon polaritons. Trilyers exhibit a magnetic-field-induced nonreciprocal effect in the surface plasmon polariton propagation. The Au/Co/Au nanosandwiches, prepared by a self-assembly process, show localized surface plasmon resonances (LSPRs) that affect the optical properties of metallic nanostructures. The fabrication of the nanostructures was performed using colloidal lithography (CL). An atomic force microscopy was used to analyze the structure of thin films. The polar Kerr ellipticity and rotation spectra for an array of nanoparticles with identical dimensions were examined. Metal trilyer films were sputtered onto glass substrates. Results show that nanoparticles can be used for the development of high-sensitive magnetoplasmonic nanosensors with multiplexing capabilities.
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| 56. |
- Gözen, Irep, 1980, et al.
(author)
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Protocells: Milestones and Recent Advances
- 2022
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In: Small. - : Wiley. - 1613-6810 .- 1613-6829. ; 18:18
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Research review (peer-reviewed)abstract
- The origin of life is still one of humankind's great mysteries. At the transition between nonliving and living matter, protocells, initially featureless aggregates of abiotic matter, gain the structure and functions necessary to fulfill the criteria of life. Research addressing protocells as a central element in this transition is diverse and increasingly interdisciplinary. The authors review current protocell concepts and research directions, address milestones, challenges and existing hypotheses in the context of conditions on the early Earth, and provide a concise overview of current protocell research methods.
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| 57. |
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| 58. |
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| 59. |
- Hamedi, Mahiar, et al.
(author)
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Electronic Polymers and DNA Self-assembled in Nanowire Transistors
- 2013
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In: Small. - : Wiley-VCH Verlag Berlin. - 1613-6810 .- 1613-6829. ; 9:3, s. 363-368
-
Journal article (peer-reviewed)abstract
- In this study the fully acidic form of PEDOT-S was used for the purpose of self-assembly onto DNA. We have previously shown that PEDOT-S is a short polymer that is self-doped with !1/3 of the sulfonate side groups acting as the self-doping sites (see supporting info.). The remaining sulfonate groups contribute to a net anionic charge, and a water-soluble polymer, with an intrinsic bulk conductivity of around 30 S/cm. It has been shown that PEDOT-S can bind to oppositely charged cationic amyloid protein structures in water and form conducting nano fibrillar networks, and it has also been shown to form hybrid structures with synthetic peptides, and gold nanoparticles.
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| 60. |
- Hammond, Oliver S., et al.
(author)
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Molecular Architecture Effects on Bulk Nanostructure in Bis(Orthoborate) Ionic Liquids
- 2023
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In: Small. - : John Wiley and Sons Inc. - 1613-6810 .- 1613-6829. ; 29
-
Journal article (peer-reviewed)abstract
- A series of 19 ionic liquids (ILs) based on phosphonium and imidazolium cations of varying alkyl-chain lengths with the orthoborate anions bis(oxalato)borate [BOB]−, bis(mandelato)borate, [BMB]− and bis(salicylato)borate, [BScB]−, are synthesized and studied using small-angle neutron scattering (SANS). All measured systems display nanostructuring, with 1-methyl-3-n-alkyl imidazolium-orthoborates forming clearly bicontinuous L3 spongelike phases when the alkyl chains are longer than C6 (hexyl). L3 phases are fitted using the Teubner and Strey model, and diffusely-nanostructured systems are primarily fitted using the Ornstein-Zernicke correlation length model. Strongly-nanostructured systems have a strong dependence on the cation, with molecular architecture variation explored to determine the driving forces for self-assembly. The ability to form well-defined complex phases is effectively extinguished in several ways: methylation of the most acidic imidazolium ring proton, replacing the imidazolium 3-methyl group with a longer hydrocarbon chain, substitution of [BOB]− by [BMB]−, or exchanging the imidazolium for phosphonium systems, irrespective of phosphonium architecture. The results suggest there is only a small window of opportunity, in terms of molecular amphiphilicity and cation:anion volume matching, for the formation of stable extensive bicontinuous domains in pure bulk orthoborate-based ILs. Particularly important for self-assembly processes appear to be the ability to form H-bonding networks, which offer additional versatility in imidazolium systems. © 2023 The Authors.
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