High-performance infrared light sources have significantly influenced the fields of photonics and optoelectronics. However, achieving infrared light emission with low energy consumption, high brightness, and rapid response remains a huge challenge. Single-walled carbon nanotubes (SWCNTs) could be an important candidate for infrared light emitters because of their superior electron mobility and phonon transport efficiency.
View Article and Find Full Text PDFIt is important to develop a wideband THz absorber for the prevention of terahertz electromagnetic pollution and information leakage. Some commonly used methods, such as metamaterials or dynamic modulation technology, have played important roles in the study of wideband THz absorbers. However, most of these absorbers are rigid or non-stretchable, which limits the practical applications in large mechanical deformation and non-plane scenarios.
View Article and Find Full Text PDFTerahertz (THz) absorbers based on the Salisbury screen have attracted significant attention for high absorption performance and simple structure. Graphene is suitable for high-performance THz absorbers due to its extraordinary electronic and optical properties. The study of graphene THz absorbers based on Salisbury screens has attracted great interest, where the number of graphene layers significantly affects the interface impedance matching and absorption efficiency.
View Article and Find Full Text PDFThe gate-tunable absorption properties of graphene make it suitable for terahertz (THz) absorbers. However, the realization of a graphene-based THz absorber faces challenges between the difficulty of patterning graphene for processing and the intrinsically low absorbance of graphene with the high electric field needed to change the conductivity of graphene. This report presents an electrically tunable graphene THz absorber where a single-layer graphene film and a gold reflective layer are separated by a polyimide (PI) dielectric layer to form an easily fabricated three-layer Salisbury screen structure.
View Article and Find Full Text PDFSandwich-type structure based on Salisbury screen effect is a simple and effective strategy to acquire high-performance terahertz (THz) absorption. The number of sandwich layer is the key factor that affects the absorption bandwidth and intensity of THz wave. Traditional metal/insulant/metal (M/I/M) absorber is difficult to construct multilayer structure because of low light transmittance of the surface metal film.
View Article and Find Full Text PDFObtaining highly purified intact living cells from complex environments has been a challenge, such as the isolation of circulating tumor cells (CTCs) from blood. In this work, we demonstrated an acoustic-based ultra-compact device for cell sorting, with a chip size of less than 2 × 1.5 cm.
View Article and Find Full Text PDFACS Appl Mater Interfaces
December 2022
Smart windows with tunable optical properties for energy-saving and privacy protection applications are receiving increasing attention. However, current studies of smart windows either involve the use of complex material preparation processes and complex device systems for window switching or continue to face several challenges, including low luminous transmittance, low luminous and solar modulation, and narrow wavelength range management problems. Here, we report a dual-responsive smart window that achieves solar light management in the range of 200-2500 nm.
View Article and Find Full Text PDFGraphene is an attractive material for terahertz (THz) absorbers because of its tunable Fermi-Level (E). It has become a research hotspot to modulate the E of graphene and THz absorption of graphene. Here, a sandwich-structured single layer graphene (SLG)/ Polyimide (PI)/Au THz absorber was proposed, and top-layer graphene was doped by HAuCl solutions.
View Article and Find Full Text PDFThe seeking of resonator with high Q and low insertion loss is attractive for critical sensing scenes based on the surface acoustic wave (SAW). In this work, 128° YX LiNbO-based SAW resonators were utilized to optimize the output performance through IDT structure parameters. Once the pairs of IDTs, the acoustic aperture, the reflecting grid logarithm, and the gap between IDT and reflector are changed, a better resonance frequency of 224.
View Article and Find Full Text PDFMicromachines (Basel)
February 2022
It is a great challenge to detect in-situ high-frequency vibration signals for extreme environment applications. A highly sensitive and robust vibration sensor is desired. Among the many piezoelectric materials, single-crystal lithium niobate (LiNbO) could be a good candidate to meet the demand.
View Article and Find Full Text PDFAn integration technology for wafer-level LiNbO single-crystal thin film on Si has been achieved. The optimized spin-coating speed of PI (polyimide) adhesive is 3500 rad/min. According to Fourier infrared analysis of the chemical state of the film baked under different conditions, a high-quality PI film that can be used for wafer-level bonding is obtained.
View Article and Find Full Text PDFGraphene nanostructures are widely perceived as a promising material for fundamental components; their high-performance electronic properties offer the potential for the construction of graphene nanoelectronics. Numerous researchers have paid attention to the fabrication of graphene nanostructures, based on both top-down and bottom-up approaches. However, there are still some unavoidable challenges, such as smooth edges, uniform films without folds, and accurate dimension and location control.
View Article and Find Full Text PDFMicromachines (Basel)
January 2021
In situ measurements of sensing signals in space platforms requires that the micro-electro-mechanical system (MEMS) sensors be located directly at the point to be measured and in contact with the subject to be measured. Traditional radiation-tolerant silicon-based MEMS sensors cannot acquire spatial signals directly. Compared to silicon-based structures, LiNbO single crystalline has wide application prospects in the aerospace field owing to its excellent corrosion resistance, low-temperature resistance and radiation resistance.
View Article and Find Full Text PDFDomain engineering plays a pivotal role in the development of ferroelectric non-volatile memory devices. In this work, we mainly focus on the domain kinetic in ion-sliced single crystal LiNbO thin films under tip-induced electric fields using piezoresponse force microscope (PFM). Polarization reversal takes place when the electric fields are above threshold value (coercive voltage V ) of films.
View Article and Find Full Text PDFFano resonance can be achieved by the destructive interference between a superradiant bright mode and a subradiant dark mode. A variety of artificial plasmonic oligomers have been fabricated to generate Fano resonance for its extensive applications. However, the Fano resonance in plasmonic oligomer systems comes from the interaction of all metal particles, which greatly limits the tunability of the Fano resonance.
View Article and Find Full Text PDFSensors (Basel)
September 2019
As a promising functional material, ferroelectric Pb(ZrTi)O (PZT) are widely used in many optical and electronic devices. Remarkably, as the film thickness decreases, the materials' properties deviate gradually from those of solid materials. In this work, multilayered PZT thin films with different thicknesses are fabricated by Sol-Gel technique.
View Article and Find Full Text PDFLayered semiconductors such as transition metal dichalcogenides (TMDs) with proper bandgaps complement the zero-bandgap drawback of graphene, demonstrating great potential for post-silicon complementary metal-oxide-semiconductor technology. Among the TMD family, molybdenum disulfide (MoS) is highly attractive for its atomically thin body, large bandgap and decent mechanical and chemical stability. However, current nanofabrication techniques hardly satisfy the requirements of short channel and convenient preparation simultaneously.
View Article and Find Full Text PDFReliable fabrication of gold nanoparticles with desirable size, geometry and spatial arrangement is essential for plasmonic applications. A common fabrication flow usually involves electron-beam lithography and a vacuum-evaporation-based lift-off process or etching. In this work, we evaluate an alternative approach to directly fabricate a plasmonic gold nanoparticle array without involving the vacuum evaporation process by using a chloroauric acid/poly(vinyl pyrrolidone) (HAuCl4/PVP) hybrid as a functional electron-beam resist.
View Article and Find Full Text PDFTransient electronics, a new generation of electronics that can physically or functionally vanish on demand, are very promising for future "green" security biocompatible electronics. At the same time, hardware implementation of biological synapses is highly desirable for emerging brain-like neuromorphic computational systems that could look beyond the conventional von Neumann architecture. Here, a hardware-security physically-transient bidirectional artificial synapse network based on a dual in-plane-gate Al-Zn-O neuromorphic transistor was fabricated on free-standing laterally-coupled biopolymer electrolyte membranes (sodium alginate).
View Article and Find Full Text PDFWe report an electron-beam lithography process to directly fabricate graphene@copper composite patterns without involving metal deposition, lift-off and etching processes using copper naphthenate as a high-resolution negative-tone resist. As a commonly used industrial painting product, copper naphthenate is extremely cheap with a long shelf time but demonstrates an unexpected patterning resolution better than 10 nm. With appropriate annealing under a hydrogen atmosphere, the produced graphene@copper composite patterns show high conductivity of ∼400 S cm.
View Article and Find Full Text PDFFocused ion beam (FIB) milling is a versatile maskless and resistless patterning technique and has been widely used for the fabrication of inverse plasmonic structures such as nanoholes and nanoslits for various applications. However, due to its subtractive milling nature, it is an impractical method to fabricate isolated plasmonic nanoparticles and assemblies which are more commonly adopted in applications. In this work, we propose and demonstrate an approach to reliably and rapidly define plasmonic nanoparticles and their assemblies using FIB milling via a simple "sketch and peel" strategy.
View Article and Find Full Text PDFWe report a method to reliably and efficiently fabricate high-fidelity metallic structures from a ten-nanometer to a millimeter scale based on an anti-ultrasonic-stripping (AUS) effect in confined micro/nanoscale cavities. With this AUS effect, metallic structures, which are surrounded by the pre-patterned closed templates, could be defined through selectively removing the evaporated metallic layer at the top and outside of the templates by ultrasonic-cavitation-induced stripping. Because only pre-patterned templates are required for exposure in this multiscale patterning process, this AUS-based process enables much smaller and more reliable plasmonic nanogaps due to the mitigated proximity effect and allows rapid fabrication of multiscale metallic structures which require both tiny and large structures.
View Article and Find Full Text PDF