- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Dynamic Structural Color from Wrinkled Thin Films
摘要： Structural color caused by thin-film interference is widespread and simple in nature. Many researchers have already showed the reversible color change of structural color system, but it is difficult to regulate dynamically with tunable intensity and viewable angle. Herein, a dynamic structural color platform is reported by combining spontaneous thin film interference and wrinkling phenomenon in nature. This robust yet low cost strategy enables large-scale and spatially arbitrary preparation of a uniform structural color surface through the whole visible spectral range. Furthermore, the prepared isotropic and anisotropic structural colors on disordered and ordered wrinkled thin films (WTFs) exhibit different optical properties that can be precisely and reversibly regulated by ultraviolet (UV) light and near-infrared (NIR) light irradiation. This exquisite and tunable structural color platform may find applications in information storage, smart display, anticounterfeiting and encryption.
关键词： dynamic structural color,tunable viewable angle,thin film,reversible wrinkle
更新于2025-09-23 15:19:57
-
A fully electronically tunable millimeter wave lab-in-waveguide nano-fluidic sensor
摘要： In this paper, we report an ultra-sensitive millimeter wave (mm-wave) reflection liquid sensor, which is electronically tunable, non-invasive, and label-free. The reflection liquid sensor is based on the impedance match technique. It is implemented in a rectangular waveguide structure, which makes the interaction between mm-wave and liquid under test (LUT) in a closed environment, forms a nano-fluidic lab-in-waveguide liquid sensor, and isolates the interference of surroundings. The reflection liquid sensor shows high sensitivity to permittivity change of the LUTs. Taking the ethanol-distilled water as benchmark, a more than 62 dB ethanol-distilled water contrast is experimentally achieved. The detection limit is 0.05% ethanol in volumetric concentration with a 4 dB signal difference, which is the best performance of the microwave and mm-wave liquid sensors publicly reported until now. The ultra-sensitive reflection sensor can be used for bio-chemical sensing. The lab-in-waveguide biosensor is also compatible with microfluidics.
关键词： impedance match,electronically tunable,liquid sensor,label-free,millimeter wave,non-invasive
更新于2025-09-23 15:19:57
-
A Broadband Tunable Terahertz Metamaterial Absorber Based on Single-Layer Complementary Gammadion-Shaped Graphene
摘要： We present a simple design of a broadband tunable metamaterial absorber (MMA) in the terahertz (THz) region, which consists of a single layer complementary gammadion-shaped (CGS) graphene sheet and a polydimethylsiloxane (PDMS) dielectric substrate placed on a continuous metal film. The Fermi energy level (Ef) of the graphene can be modulated dynamically by the applied DC bias voltage, which enables us to electrically control the absorption performance of the proposed MMA flexibly. When Ef = 0.8 eV, the relative bandwidth of the proposed MMA, which represents the frequency region of absorption beyond 90%, can reaches its maximal value of 72.1%. Simulated electric field distributions reveal that the broadband absorption mainly originates from the excitation of surface plasmon polaritons (SPPs) on the CGS graphene sheet. Furthermore, the proposed MMA is polarization-insensitive and has wide angles for both transverse-electric (TE) and transverse-magnetic (TM) waves in the broadband frequency range. The broadband absorption capacity of the designed MMA can be effectively adjusted by varying the Fermi energy level of graphene. Lastly, the absorbance of the MMA can be adjusted from 42% to 99.1% by changing the Ef from 0 eV to 0.8 eV, which is in agreement with the theoretical calculation by using the interference theory. Due to its simple structure and flexible tunability, the proposed MMA has potential application prospects in tunable filtering, modulators, sensing, and other multispectral devices.
关键词： graphene,surface plasmon polaritons,broadband tunable absorption,terahertz metamaterial absorber
更新于2025-09-23 15:19:57
-
Thermal design management of highly mechanically stable wavelength shifter using photonic crystal waveguide
摘要： A thermally tunable device based on photonic crystal waveguide integrated with the micro-hotplate on its surface is proposed. A design strategy for modelling of temperature and stress in the MHP is investigated for providing robustness and high mechanical stability in the reconfigurable device. The required temperature is obtained under stress elongation fatigue limit for thermal tuning applications in optical devices. The performance parameters like confinement factor, wavelength transfer coefficient and extinction ratio are obtained as 78.2%, 0.086 nm/K and 30.04 dB respectively with an excess loss of only 0.20 dB. The response-time in the optimized device is 12 μs for achieving the switching spectral shift of 26 nm in the transmission spectrum of PCW. The reconfigurable device platform offers a great potential for wide range of tuning in switches and filters applications
关键词： Thermally tunable device,Photonic crystal waveguide,Thermo-optic tuning,Mechanical stability,Micro-hotplate
更新于2025-09-23 15:19:57
-
Tuning the Color Palette of Semi-Transparent Solar Cells via Lateral ??-Extension of Polycyclic Heteroaromatics of Donora??Acceptor Dyes
摘要： Durable solar cells with tunable color and diaphaneity are very promising for building integrated photovoltaic applications. In this paper we employ donor–acceptor organic dyes U3, U4, U5, and R6 featured by polycyclic heteroaromatics 6,12-dihydroindeno[1,2-b]indeno[2',1':4,5]thieno[2,3-d]thiophene (IT2), 7,15-dihydrobenzo[6',7']indeno[2',1':4,5]thieno[3,2-b]benzo[6,7]indeno[2,1-d]thiophene (BIT2), 7,15-dihydrophenaleno[1,2-b]phenaleno[2',1':4,5]thieno[2,3-d]thiophene (PT2), and 9,19-dihydrobenzo[1',10']phenanthro[3',4':4,5]thieno[3,2-b]benzo[1,10]phenanthro[3,4-d]thiophene (BPT2) to fabricate semi-transparent dye-sensitized solar cells (DSSCs). The U3, U4, U5, and R6 based cells are goldenrod, crimson, red, and sapphire blue, with power conversion efficiencies of 3.5%, 8.2%, 7.6, and 10.1% at the AM1.5G conditions. Density functional theory calculation and voltammetric measurement reveal that lateral π-extension of polycyclic heteroaromatic brings forth a downward displacement of lowest unoccupied molecular orbital, affording a high molar extinction coefficient, low-energy gap blue dye. Femtosecond fluorescence decay measurements of dyed titania and alumina films unravel the electron injection yields of photo-excited dye molecules, which are well correlated with the maximal values of external quantum efficiencies of DSSCs. After 1,000 h full sunlight soaking at 60 oC, the red and blue DSSCs exhibit stable photocurrents, owing to the strong bonding and photochemical stability of dye molecules adsorbed on the surface of titania as well as the retention of close-to-unity electron collection yield.
关键词： electron injection,durability,tunable color,semi-transparent solar cell,lateral π-extension,photosensitizer
更新于2025-09-23 15:19:57
-
Controlling Nucleation Process of InP/ZnS Quantum Dots Using Zeolite as A Nucleation Site
摘要： As a representative of III-V semiconductor materials, InP/ZnS quantum dots are regarded as the star material in the field of light-emitting devices due to their low toxicity and suitable luminescence range. However, there are still some major problems in the preparation process of InP/ZnS QDs, such as phosphine precursors are expensive and difficult to preserve and the nucleation time of short wavelength InP/ZnS QDs is too short and the size distribution is too large. In this paper, we'll replace the traditional tris(trimethylsilyl)phosphine with the tris(diethylamino)phosphine as a cheaper phosphine precursor and propose a novel and convenient method for adjusting the luminescence wavelength of InP/ZnS QDs. Different from the traditional method to adjust the emission wavelength by changing the nucleation time, the emission wavelength of InP/ZnS QDs was regulated by changing the number of initially formed cores. Zeolites do duty for providing a nucleation site for the InP cores. The InP/ZnS QDs emitted from 522 nm to 589 nm were obtained. Moreover, the obtained InP/ZnS QDs has good monochromaticity, the minimum half-width (half-full width) up to 48 nm. This method provides a new way to adjust the size of quantum dots with good performance.
关键词： Zeolites,Indium phosphide,Color tunable,Quantum dots,nucleation site
更新于2025-09-23 15:19:57
-
Self-driven all-inorganic perovskite microplatelet vertical Schottky junction photodetectors with a tunable spectral response
摘要： Wavelength-selective perovskite photodetectors (PDs) have many applications in optoelectronic field, such as machine vision, imaging and full-color display. However, the instability of organo-inorganic hybrid perovskite material severely limits the commercialization of perovskite-based PDs. In this work, a more stable all-inorganic perovskite, CsPbBr(3-x)Clx (x = 0, 1, 2, 3) microplatelets (MPs), were employed to fabricate Schottky PDs with a simple vertical structure of ITO/MP/Au. The optimized CsPbBr3 MP Schottky PDs exhibit rapid response speed (75 μs) and very low dark current (2 pA) at zero bias. Meanwhile, the device shows a high on/off ratio (>106), a large specific detectivity (>1012 Jones) and linear dynamic range (LDR = 137 dB) with excellent thermal and long-term stability. Furthermore, a tunable spectral response covering from the ultraviolet to visible range is also demonstrated. These results provide a simple avenue to realize self-driven and spectral tunable all-inorganic perovskite Schottky PDs with good stability.
关键词： all-inorganic perovskite,high temperature tolerance,tunable spectral response,vertical structure Schottky photodetector,weak-light sensitivity
更新于2025-09-23 15:19:57
-
Gate Tunable Symmetric Bipolar Junction Transistor Fabricated via Femtosecond Laser Processing
摘要： Two-dimensional (2D) bipolar junction transistor (BJT) with van der Waals heterostructures plays an important role in the development of future nanoelectronics. Herein, a convenient method is introduced for fabricating a symmetric bipolar junction transistor (SBJT) constructed with black phosphorus and MoS2 with femtosecond laser processing. This SBJT exhibits good bidirectional current amplification thanks to its symmetric structure. Next, we place a top gate on one side of the SBJT to change the difference in the major carrier concentration between the emitter and collector in order to further investigate the effect of electrostatic doping on the device’s performance. The SBJT can also act as a gate tunable phototransistor with good photodetectivity and photocurrent gain of β ~ 21. Scanning photocurrent images are used to determine the mechanism governing photocurrent amplification in the phototransistor. These results promote the development of the applications of multifunctional nanoelectronics based on 2D materials.
关键词： Femtosecond laser processing,Phototransistor,Two-dimensional materials,Bipolar junction transistor,Gate tunable
更新于2025-09-23 15:19:57
-
Tunable Microlasers Modulated by Intracavity Spherical Confinement with Chiral Liquid Crystal
摘要： Manipulation of laser emission offers promising opportunities for the generation of new spatial dimensions and applications, particularly in nanophotonics, super-resolution imaging, and data transfer devices. However, the ability to control laser modes and wavelength in a microcavity remains challenging. Here, a novel approach is demonstrated to control laser modes by manipulating the 3D-optical confinement, chirality, and orientations in a Fabry?Pérot microcavity with cholesteric liquid crystal droplets. Different configurations of intracavity micro-/nanostructures generate versatile dimensions of laser modes, while the significantly reduced laser mode volume further leads to single-mode lasing. Theoretical analysis is carried out to support this interesting discovery. Finally, switchable lasing wavelength with various surface anchoring forces and pH interactions is demonstrated. This novel concept not only provides a simple yet highly versatile method to manipulate laser emissions, but deepens insight into how molecules interact with and modulate laser light, laying the foundation for the development of tunable photonic devices at the molecular level. Promising applications include highly selective laser devices, laser-emission imaging, and bioinspired sensing.
关键词： tunable lasing,high-order laser mode,cholesteric liquid crystals,spherical confinement,intracavity interactions
更新于2025-09-23 15:19:57
-
Investigation of polycrystalline Ga <sub/>x</sub> In <sub/>1a??a??a??x</sub> P for potential use as a solar cell absorber with tunable bandgap
摘要： There is ongoing interest in developing a stable, low-cost, 1.6–1.8 eV top-cell material that can be used for two-junction (tandem) solar cells, particularly in combination with a silicon bottom cell. In this work, polycrystalline GaInP is grown and characterized to explore its properties and use for this purpose. The film composition and deposition temperature are varied to determine their effects on grain size, morphology, and photoluminescence (PL) over a range of bandgaps from 1.35 to 1.7 eV. An Al-assisted post-deposition treatment for 1.7-eV polycrystalline GaInP results in a 90-fold increase in peak photoluminescence (PL) intensity, a 220-fold increase in integrated PL intensity, and increased time-resolved PL lifetime from <2 ns to 44 ns. The increase in PL intensity and lifetime is attributed to a reduction of nonradiative minority-carrier recombination at the top surface, and at grain boundaries near the surface, due to the formation of a higher-bandgap AlGaInP alloy. These materials provide a viable path toward increased minority-carrier concentration under illumination and improved recombination properties needed for high-efficiency tandem solar cells.
关键词： polycrystalline GaInP,tunable bandgap,post-deposition treatment,photoluminescence,solar cell
更新于2025-09-23 15:19:57