- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Image charge effect on the light emission of rutile TiO <sub/>2</sub> (110) induced by a scanning tunneling microscope
摘要： The plasmon-enhanced light emission of rutile TiO2(110) surface has been investigated by a low-temperature scanning tunneling microscope (STM). We found that the photon emission arises from the inelastic electron tunneling between the STM tip and the conduction band or defect states of TiO2(110). In contrast to the Au(111) surface, the maximum photon energy as a function of the bias voltage clearly deviates from the linear scaling behavior, suggesting the non-negligible effect of the STM tip on the band structure of TiO2. By performing differential conductance (dI/dV) measurements, it was revealed that such a deviation is not related to the tip-induced band bending, but is attributed to the image charge effect of the metal tip, which significantly shifts the band edges of the TiO2(110) towards the Femi level (EF) during the tunneling process. This work not only sheds new lights onto the understanding of plasmon-enhanced light emission of semiconductor surfaces, but also opens up a new avenue for engineering the plasmon-mediated interfacial charge transfer in molecular and semiconducting materials.
关键词： TiO2,scanning tunneling microscopy,light emission,plasmon
更新于2025-09-23 15:22:29
-
Multicolor emission from non-conjugated polymers based on a single switchable boron chromophore
摘要： Multicolor emissive and responsive materials are highly attractive due to their potential applications in various fields, and polymers are preferred for their good processability and high stability. Herein, we report a series of new polymers based on a methacrylate monomer containing a switchable boron chromophore. In spite of the unconjugated nature, interestingly, the homopolymers from this monomer display rare multicolor fluorescence in solution that is highly dependent on the degree of polymerization (DP). With an ascending DP, the local concentration of the chromophore increases, leading to a higher propensity for switching the blue emitting tricoordinate boron chromophore to the red emitting tetracoordinate one. The homopolymers also display temperature and solvent-dependent emission colour change. Furthermore, pure white-light emission could be achieved in various solvents by precisely tuning the homopolymer molecular weight, or in films/solid state by copolymerizing the emissive boron monomer with non-emissive monomers in an appropriate ratio.
关键词： Multi-responsiveness,Non-conjugated Polymer,Single Chromophore,White Light Emission,Multicolor Emission
更新于2025-09-23 15:21:21
-
Efficient and stable emission of warm-white light from lead-free halide double perovskites
摘要： Lighting accounts for one-fifth of global electricity consumption1. Single materials with efficient and stable white-light emission are ideal for lighting applications, but photon emission covering the entire visible spectrum is difficult to achieve using a single material. Metal halide perovskites have outstanding emission properties2,3; however, the best-performing materials of this type contain lead and have unsatisfactory stability. Here we report a lead-free double perovskite that exhibits efficient and stable white-light emission via self-trapped excitons that originate from the Jahn–Teller distortion of the AgCl6 octahedron in the excited state. By alloying sodium cations into Cs2AgInCl6, we break the dark transition (the inversion-symmetry-induced parity-forbidden transition) by manipulating the parity of the wavefunction of the self-trapped exciton and reduce the electronic dimensionality of the semiconductor4. This leads to an increase in photoluminescence efficiency by three orders of magnitude compared to pure Cs2AgInCl6. The optimally alloyed Cs2(Ag0.60Na0.40)InCl6 with 0.04 per cent bismuth doping emits warm-white light with 86 ± 5 per cent quantum efficiency and works for over 1,000 hours. We anticipate that these results will stimulate research on single-emitter-based white-light-emitting phosphors and diodes for next-generation lighting and display technologies.
关键词： lead-free halide double perovskites,self-trapped excitons,white-light emission,photoluminescence efficiency,Jahn–Teller distortion
更新于2025-09-23 15:21:21
-
Ratiometric Luminescent Sensor of Picric Acid based on the Dual-Emission Mixed-Lanthanide Coordination Polymer
摘要： Powerful explosive sensors play a key role in public security and environmental protection. Herein we report a series of isostructural lanthanide coordination polymers [Ln2L1.5(NMP)2]n (LnL, Ln = Eu , Gd, Tb, Dy, Ho and Er, H4L = [1,1′:4′,1″-terphenyl]-2′,4,4″,5′-tetracarboxylic acid, NMP = N-methyl-2-pyrrolidone) and mixed-Ln LnL (EuxTb1-xL, EuxGd1-xL, TbxGd1-xL and EuxTb0.02-xGd0.98L). Luminescence studies show that both H4L and GdL emit strong fluorescence and phosphorescence at 77 K while only fluorescence at room temperature, and TbL exhibits strong Tb3+ characteristic emission though the energy difference between the triplet excited state of H4L (20661 cm-1) and the 5D4 energy level of Tb3+ (20500 cm-1) is very small. By doping Eu3+ and Tb3+ into GdL, we obtained EuxTb0.02-xGd0.98L emitting warm white light. For TbL and Tb0.01Gd0.99L showing the dual-emission, upon addition of picric acid (PA) into their suspensions in Tris-HCl buffer, Tb3+ emission decreases slowly, however, the ligand-based emission is sharply quenched, rendering TbL and Tb0.01Gd0.99L excellent single-lanthanide and mixed-lanthanide ratiometric luminescence PA sensor materials, respectively.
关键词： picric acid (PA),ratiometric luminescence sensors,white light emission,metal-organic frameworks (MOFs),Coordination polymers (CPs)
更新于2025-09-23 15:21:21
-
Tunable topological charge vortex microlaser
摘要： The orbital angular momentum (OAM) intrinsically carried by vortex light beams holds a promise for multidimensional high-capacity data multiplexing, meeting the ever-increasing demands for information. Development of a dynamically tunable OAM light source is a critical step in the realization of OAM modulation and multiplexing. By harnessing the properties of total momentum conservation, spin-orbit interaction, and optical non-Hermitian symmetry breaking, we demonstrate an OAM-tunable vortex microlaser, providing chiral light states of variable topological charges at a single telecommunication wavelength. The scheme of the non–Hermitian-controlled chiral light emission at room temperature can be further scaled up for simultaneous multivortex emissions in a flexible manner. Our work provides a route for the development of the next generation of multidimensional OAM-spin-wavelength division multiplexing technology.
关键词： data multiplexing,orbital angular momentum,chiral light emission,non-Hermitian symmetry breaking,vortex light beams,spin-orbit interaction,microlaser,telecommunication wavelength
更新于2025-09-23 15:21:01
-
[IEEE 2019 Joint International EUROSOI Workshop and International Conference on Ultimate Integration on Silicon (EUROSOI-ULIS) - Grenoble, France (2019.4.1-2019.4.3)] 2019 Joint International EUROSOI Workshop and International Conference on Ultimate Integration on Silicon (EUROSOI-ULIS) - InAs Electron-Hole Bilayer LED
摘要： We report a novel switched-mode light-emitting device (LED) in an undoped ultra-thin body (UTB) InAs channel based on the electrostatically induced electron-hole (EH) bilayer concept. The induced EH channels at their respective gate interfaces, which remain spatially separated in steady state, gradually diffuse and recombine during a switch-off transient. Using TCAD simulations, we show that continuous switching of the gates with a ～ 12 μs time period leads to radiative recombination of the induced charge carriers with a peak internal quantum ef?ciency (IQE) as high as ～ 92%. The proposed concept obviates the need for chemically doped p-n junctions in the UTB device for light emitting applications and could also be employed for other direct bandgap semiconductors. However, the switching speed is ultimately limited by the thermal generation time.
关键词： ultra-thin body,thermal generation,light emission,Electrostatic doping,III-V on-insulator
更新于2025-09-23 15:21:01
-
Electrogenerated Chemiluminescence and Spectroelectrochemistry Characteristics of Blue Photoluminescence Perovskite Quantum Dots
摘要： Lead-based perovskite MAPbX3 (MA= CH3NH3, X=Cl and Br) has shown great potential benefits to advance modern optoelectronics and clean energy harvesting devices. Poor structural stability is one of the major challenges of MAPbX3 perovskite materials to overcome to achieve desired device performance. Here we present the electrochemical stability study of CH3NH3PbCl1.08Br1.92 quantum dots (QDs) by electrogenerated chemiluminescence (ECL) and photoluminescence (PL) spectroelectrochemistry methods. Electrochemical anodization of pristine MAPbX3 QD film results in the disproportionate loss of methylammonium and halide ions (X=Cl and Br). ECL efficiency and stability of perovskite QDs in the presence of co-reactant tripropyl amine (TPrA) can be greatly improved after being incorporated into a polystyrene (PS) matrix. Mass spectrum and X-ray photoelectron spectroscopy (XPS) measurements are used to provide chemical composition variation details of QDs, responsible for the ECL and PL characteristics (e.g., wavelength redshift) of perovskite QDs in an electrochemical cell.
关键词： quantum dots (QDs),Perovskite,Blue light emission,nanocrystals,polystyrene (PS),electrogenerated chemiluminescence (ECL),photoluminescence (PL)
更新于2025-09-23 15:21:01
-
Lighta??Emitting Nanophotonic Designs Enabled by Ultrafast Laser Processing of Halide Perovskites
摘要： Nanophotonics based on resonant nanostructures and metasurfaces made of halide perovskites have become a prospective direction for efficient light manipulation at the subwavelength scale in advanced photonic designs. One of the main challenges in this field is the lack of large-scale low-cost technique for subwavelength perovskite structures fabrication preserving highly efficient luminescence. Here, unique properties of halide perovskites addressed to their extremely low thermal conductivity (lower than that of silica glass) and high defect tolerance to apply projection femtosecond laser lithography for nanofabrication with precise spatial control in all three dimensions preserving the material luminescence efficiency are employed. Namely, with CH3NH3PbI3 perovskite highly ordered nanoholes and nanostripes of width as small as 250 nm, metasurfaces with periods less than 400 nm, and nanowire lasers as thin as 500 nm, corresponding to the state-of-the-art in multistage expensive lithographical methods are created. Remarkable performance of the developed approach allows to demonstrate a number of advanced optical applications, including morphology-controlled photoluminescence yield, structural coloring, optical-information encryption, and lasing.
关键词： metasurfaces,structural coloration,lasing,halide perovskites,light emission,nanostructures
更新于2025-09-23 15:19:57
-
Chemo- and magnetotaxis of self-propelled light emitting chemo-electronic swimmers
摘要： Miniaturized autonomous chemo-electronic swimmers, based on the coupling of spontaneous oxidation and reduction reactions at the two poles of light emitting diodes (LEDs), are presented as chemotactic and magnetotactic devices. In homogeneous aqueous media, random motion caused by a bubble-induced propulsion mechanism, is observed. However, in an inhomogeneous environment, the self-propelled devices exhibit positive chemotactic behavior, propelling themselves along a pH or ionic strength gradient (?pH, ?I, respectively) in order to reach a thermodynamically higher active state. In addition, the intrinsic permanent magnetic moment of the LED allows self-orientation in the terrestrial magnetic field or following other external magnetic perturbations, which enables a directional motion control coupled with light emission. The interplay between chemotaxis and magnetotaxis allows fine-tuning the dynamic behavior of these swimmers.
关键词： electronic swimmers,magnetotaxis,pH gradient,Chemotaxis,light emission
更新于2025-09-23 15:19:57
-
Chemoa?? and magnetotaxis of selfa??propelled light emitting chemoa??electronic swimmers
摘要： Miniaturized autonomous chemo-electronic swimmers, based on the coupling of spontaneous oxidation and reduction reactions at the two poles of light emitting diodes (LEDs), are presented as chemotactic and magnetotactic devices. In homogeneous aqueous media, random motion caused by a bubble-induced propulsion mechanism, is observed. However, in an inhomogeneous environment, the self-propelled devices exhibit positive chemotactic behavior, propelling themselves along a pH or ionic strength gradient (?pH, ?I, respectively) in order to reach a thermodynamically higher active state. In addition, the intrinsic permanent magnetic moment of the LED allows self-orientation in the terrestrial magnetic field or following other external magnetic perturbations, which enables a directional motion control coupled with light emission. The interplay between chemotaxis and magnetotaxis allows fine-tuning the dynamic behavior of these swimmers.
关键词： electronic swimmers,magnetotaxis,pH gradient,Chemotaxis,light emission
更新于2025-09-23 15:19:57