- 标题
- 摘要
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- 实验方案
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Applied Nanophotonics || Lighting with nanostructures
摘要： This chapter considers application of various nanostructures in lighting devices and components. It includes an introduction to photometry and color perception by humans, and discussion of colloidal quantum dots as spectral converters in display devices and lighting sources; advances in development of colloidal quantum dot light-emitting diodes (LEDs); epitaxial quantum well structures as the core technology in solid-state lighting; the potential for metal nanostructures to improve efficiency of light sources; and the outlook for challenging issues in this field. The new trends in eye-friendly customized lighting and the lighting adapted to human biorhythms are covered, and possible application of residential lighting systems for wireless optical communication (Li-Fi) are discussed.
关键词： colloidal quantum dots,metal nanostructures,nanostructures,LEDs,Li-Fi,solid-state lighting,lighting devices
更新于2025-09-09 09:28:46
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Dark-blue titanium dioxide: Effect of phenothiazine on structural and optical properties of nanocrystalline anatase TiO2
摘要： We studied the effect of the phenothiazine (PTZ) surface doping on the structural and optical properties of nanocrystalline titanium dioxide powder with a single anatase phase (A-TiO2). We found that the mixing and interaction of PTZ and A-TiO2 leads to the intense dark-blue color of PTZ-doped A-TiO2 (A/PTZ). The appearance of new bands in the Fourier transform IR spectrum indicated the formation of PTZ?+ radical cations and reduced Ti3+species as well as extra oxygen vacancies (VO) in the TiO2 matrix. The UV-vis absorption spectrum of A/PTZ exhibited a strong increase in absorption in the visible region (>400 nm). The doping of A-TiO2 with PTZ causes a noticeable redshift of the absorption edge and a significant narrowing of the band gap by 0.24 and 0.49 eV for direct and indirect electronic transitions, respectively. The photoluminescence spectra show that the photoluminescence originating from Ti3+ and [VO-Ti3+] states for A/PTZ is much stronger than for A-TiO2, but the excitonic photoluminescence of A/PTZ is quenched. An increased number of surface defects in A/PTZ can essentially increase the nonradiative charge recombination and photoluminescence quenching, and therefore may considerably enhance the photoactivity of the dark-blue TiO2 in the visible range of the spectrum.
关键词： Optical properties,Spectroscopy,Phenothiazine,Titanium dioxide,Nanostructures
更新于2025-09-09 09:28:46
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Reduced graphene oxide/metallic MoSe2: Cu nanosheet nanostructures grown by a chemical process for highly efficient water splitting
摘要： The transition metal dichalcogenides with metallic 1T structure are attracting contemporary attention for applications in high-performance devices because of their peculiar optical and electrical properties. To date, one-step synthesis of 1T-MoSe2 is a challenge. This work presents a facile one-step synthesis of reduced graphene oxide/1T MoSe2: Cu nanosheets. The experiment results indicated that the MoSe2 prepared by simple chemical solution reaction possessed 1T structures. The reduced graphene oxide (RGO) incorporation and Cu doping did not obviously affect the phase structure but decreased the average particle size. The 1T structure, together with the Cu doping and interface effect between the MoSe2 and RGO, remarkably enhanced the conduction and photoconduction of the nanostructures. Thus, Cu doping and RGO incorporation also enhanced the hydrogen evolution catalytic activity and stability, making the RGO/MoS2: Cu nanosheet a most active and stable catalyst for hydrogen evolution.
关键词： MoSe2,Water splitting,Graphene,Metallic structure,Nanostructures
更新于2025-09-09 09:28:46
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Surface induced charge transfer in CuxIn2-xS3 nanostructures and their enhanced photoelectronic and photocatalytic performance
摘要： Multi-functional semiconducting nanostructures are gaining popularity for application in photoelectronics, energy storage devices and also in industrial and environmental remediation functions. In this regard, CuxIn2-xS3 nanostructures were investigated in detail for their photoelectrical and photocatalytic performance. Their physico-chemical characteristics were at first studied using X-ray diffraction, Raman, UV–vis absorbance, X-ray photoelectron spectroscopy and high resolution electron microscopic tools. CuxIn2-xS3 based flip chip Schottky diodes were demonstrated to attest their improved conductivity and enhanced photoelectrical performance. The photo switching capabilities of a type II p-n CdTe/CuxIn2-xS3 heterojunction was also investigated. In both the device configurations, the current-voltage (I-V) characteristics revealed the forward current and rectification ratio to improve under lower threshold voltages. The time-dependent photoresponse characteristics affirmed the stability of diodes, augmenting the improved/effective separation of photo generated electron hole pairs under illumination. Additionally, the photocatalytic performances of CuxIn2-xS3 nanostructures were inferred under visible light conditions through effective remediation of methylene blue (MB) dye molecules. The obtained results infer the Cu interaction in tetragonal lattice of CuxIn2-xS3 to promote the surface induced charge transfer mechanism in respective nanostructures, thereby enhancing their photoelectronic and photocatalytic functionalities.
关键词： Nanostructures,Photodiodes,Semiconductors,Photocatalysis
更新于2025-09-09 09:28:46
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Applied Nanophotonics || Quantum confinement effects in semiconductors
摘要： Absorption and emission of light by atoms, molecules, and solids arise from electron transitions. Electron confinement phenomena in solids with restricted geometry like nanoparticles, nanorods, or nanoplatelets gives rise to the modification of optical absorption and emission spectra and transition probabilities in semiconductor nanostructures. These phenomena are direct consequences of the wave properties of electrons. In this chapter we describe size-dependent optical properties of semiconductor nanostructures related to quantum confinement.
关键词： optical absorption,semiconductors,nanostructures,emission spectra,Quantum confinement
更新于2025-09-09 09:28:46
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Applied Nanophotonics || Spontaneous emission of photons and lifetime engineering
摘要： Excited atoms, molecules, and solids emit spontaneously photons, with the rate of emission being dependent both on their intrinsic properties and the properties of ambient space. The latter is capable or not capable of carrying on certain electromagnetic modes. This property of space is described by means of the density of electromagnetic modes or, in quantum language, photon density of states. Photon density of states can be engineered in a desirable way using spatially arranged components with different dielectric permittivity on the wavelength scale. This chapter provides a brief introduction to spontaneous photon emission control in nanostructures based on confinement of electromagnetic waves to get photon density of states’ enhancement or inhibition.
关键词： nanostructures,electromagnetic waves,spontaneous emission,photon density of states,lifetime engineering
更新于2025-09-09 09:28:46
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Reconfigurable Bioinspired Framework Nucleic Acid Nanoplatform Dynamically Manipulated in Living Cells for Subcellular Imaging
摘要： In nature, the formation of spider silk fibers begins with dimerizing the pH-sensitive N-terminal domains of silk proteins (spidroins) upon lowering pH, which provides a natural masterpiece for programmable assembly. Inspired by the similarity of pH-dependent dimerization behaviors, here we introduce an i-motif-guided model to mimic the initial step of spidroin assembly at the subcellular level. A framework nucleic acid (FNA) nanoplatform is designed using two tetrahedral DNA nanostructures (TDNs) with different branched vertexes carrying a bimolecular i-motif and a split ATP aptamer. Once TDNs enter acidic lysosomes within living cells, they assemble into a hetero-dimeric architecture thereby enabling the formation of a larger-size framework and meanwhile subcellular imaging in response to endogenous ATP, which can be dynamically manipulated via adjusting intracellular pH and ATP level with external drug stimuli.
关键词： silk-mimicking,supermolecular assembly,bioinspired,DNA nanostructures,framework nucleic acids
更新于2025-09-09 09:28:46
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Gallium Oxide || Growth, properties, and applications of β-Ga2O3 nanostructures
摘要： This chapter provided a brief overview for β-Ga2O3 nanostructures from a growth aspect to device applications. The outstanding properties of β-Ga2O3 such as large bandgap, high breakdown field, thermal and chemical stability, along with advantageous properties due to its nanostructures morphology such as large surface-to-volume ratio, fewer defects, and less strain makes it a potential material for development of high-performance nanoscale devices. β-Ga2O3 nanostructures have shown great promise for nanoscale devices such as deep-UV photodetectors, gas sensors, and FETs. In addition, functional nanowires based on β-Ga2O3 nanostructures can also be utilized for establishing the nanoscale device platform.
关键词： device applications,photodetectors,FETs,β-Ga2O3 nanostructures,gas sensors,growth techniques
更新于2025-09-09 09:28:46
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Shape Tailored TiO <sub/>2</sub> Nanostructures and Their Hybrids for Advanced Energy and Environmental Applications: A Review
摘要： Shape tailored TiO2 nanostructures with various dimensionality (zero to three dimension) have unique physicochemical and functional properties that facilitates its efficient energy and environment applications, e.g., solar light driven photocatalytic hydrogen generation and decontamination of organic/inorganic toxic pollutants, CO2 reduction into the hydrocarbon fuels, solar cells, supercapacitors and lithium-ion batteries etc. However, the wide band gap nature and the fast recombination of the photogenerated charge carriers in TiO2 usually limit its overall performance under solar light illumination. In this review, we present a state of the art on the fabrication techniques of shape tailored TiO2 nanostructures and the strategies employed to make the system catalytically more efficient. Though shape tailored TiO2 nanostructures with large specific surface area and highly energetic (001) facet exposed TiO2 nanostructures (2D and 3D) can enhance the photocatalytic efficiency to a reasonable extent, further surface engineering is needed for the modification of the electronic band arrangement, visible light sensitization and efficient charge separation. Herein, TiO2 heterostructures (HSs) with metal/non-metal doping, surface fluorination, plasmonic noble metal nanoparticles (NPs) and coupling with the narrow band gap suitable semiconductor (type-II) are discussed in details covering from zero dimensional to three dimensional heterostructures. The synthesis strategies, charge transfer mechanism and their participation in the photocatalysis are elaborated. Though one dimensional TiO2 HSs have been widely studied, we present the recent development of critical surface engineering strategies of two and three dimensional systems, which give rise to the excellent properties including the enlargement of surface area, light absorption capability and efficient separation of electrons/holes resulting in the superior performance in advanced applications. Based on recent breakthroughs in the field, future directions and outlook of the field are presented at the end.
关键词： Type-II Heterostructure,2D TiO2,3D TiO2,Shape Tailored TiO2 Nanostructures,1D TiO2,Visible Light Photocatalysis,Hydrogen Production,0D TiO2,Plasmonic Heterostructure
更新于2025-09-09 09:28:46
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Current-Driven Dyakonov-Shur Instability in Ballistic Nanostructures with a Stub
摘要： We develop a compact model for the THz plasmonic unstable structures with tunable narrow-channel regions of an increased width (called plasmonic “stubs”) using the transmission line analogy and derive the dispersion equations describing unstable plasmons. The solutions of the dispersion equations in the plasmonic systems with the electron drift, which are derived using the hydrodynamic model and generalized to account for the stubs, illustrate the device physics and can be used for design and characterization of THz plasmonic-electronic sources. Our results show that adding stubs allows one to control the Dyakonov-Shur instability in plasmonic ?eld-e?ect transistors by optimizing the boundary conditions, controlling the plasma velocity, and making it possible to drive periodic plasmonic structures wirelessly, thus avoiding the contact problems.
关键词： THz plasmonic,hydrodynamic model,plasmonic stubs,Dyakonov-Shur instability,ballistic nanostructures
更新于2025-09-09 09:28:46