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A variety of chemical sensing materials and procedures for conveniently detecting mercuric ion (II) (Hg2+) have been extensively explored. The detection challenges for accomplishing a simple, fast, and low investment procedure at the ultrasensitive level are ongoing. Herein we report a quadrillionth level for detecting Hg2+ by the surface-enhanced Raman scattering (SERS) technique. There is an interaction of silver nanoparticles decorated on a zinc-oxide tetrapod structure and coated on FTO glass (Ag@ZnO-FTO) with an organic ligand. 4,4′-Dipyridyl (DPy) performed as being chemisorbed by Ag nanoparticles interacting with a pyridine ring to produce plasmonic hot spots for SERS. The morphology of the surface and porous structure of the tetrapod becomes the powerful platform for enhanced SERS performance of DPy detection. In the absence of the augmentative electrolyte, the enhancement factor for DPy is more than 107. The inhibiting of the aggregation between Ag and DPy was present following the appearance of Hg2+, demonstrated by the quenching of the SERS signal from the DPy molecules. The capability to reproduce and the selectivity of the sensing by DPy were both demonstrated. In addition, the applications for detecting Hg2+ in natural water and beverages were successfully detected. These results demonstrated the SERS sensors had the potential for detecting Hg2+ in practical use.

Rapid detection of the handiness of chiral molecules is an important topic for pharmaceutical industries because chiral drugs with opposing handiness sometimes exhibit unwanted side effects. In this research, a rapid optical method is proposed to determine the handiness of the chiral drug "Thalidomide". The platform is a large array of three-dimensional (3D) twisted metamaterials fabricated with a novel method by combining nanospherical-lens lithography (NLL) and hole-mask lithography (HML). The fabrication is high-throughput and the twisted metamaterials cover a large area. Strong circular dichroism (CD) response is observed in the near-infrared (NIR) region, which enables the chiral detection to be performed by a low-cost and portable spectroscope system. The proposed nanofabrication method significantly improves the capabilities of NLL and HML, which can be quickly adapted to fabricate various periodic 3D metamaterials. In addition, the results of this research pave the road for the rapid penetration of nanophotonics into the pharmaceutical industries.

Bioresorbable drug release platforms offer advanced treatment for hormone imbalances, malignant cancers, and diabetic conditions., Implantable drug release platforms that offer wirelessly programmable control over pharmacokinetics have potential in advanced treatment protocols for hormone imbalances, malignant cancers, diabetic conditions, and others. We present a system with this type of functionality in which the constituent materials undergo complete bioresorption to eliminate device load from the patient after completing the final stage of the release process. Here, bioresorbable polyanhydride reservoirs store drugs in defined reservoirs without leakage until wirelessly triggered valve structures open to allow release. These valves operate through an electrochemical mechanism of geometrically accelerated corrosion induced by passage of electrical current from a wireless, bioresorbable power-harvesting unit. Evaluations in cell cultures demonstrate the efficacy of this technology for the treatment of cancerous tissues by release of the drug doxorubicin. Complete in vivo studies of platforms with multiple, independently controlled release events in live-animal models illustrate capabilities for control of blood glucose levels by timed delivery of insulin.

Biologically and environmentally resorbable electronic devices support application possibilities that cannot be addressed with conventional technologies. This paper presents highly conductive, water-soluble composites that can be printed to form contacts, interconnects, antennas, and other important features that are essential to nearly all systems of this type. An optimized material formulation involves in situ polymerization to yield a polyanhydride containing a dispersion of molybdenum microparticles at appropriate concentrations. Comparisons of essential physical and electrical properties of these materials to those of composites formed with other polymers and other metal microparticles reveal the relevant considerations. Various functional demonstrations of screen-printed test structures and devices illustrate the suitability of these conductive inks for use in water-soluble electronic devices. A key advantage of the material introduced here compared to alternatives is its ability to maintain conductance over significant periods of time while immersed in relevant aqueous solutions. Studies involving live animal models establish the biocompatibility.

The electrostatic charge distribution model and the finite-difference time-domain method were used to provide a physically intuitive interpretation of how the shape and the number of branches affect the localized surface plasmon resonances of 3D sea-urchin like nanoparticles. We consider both planner and spherical structures with pins of cylindrical, triangular and hexagonal shape. Better alignment between surface charges of opposite sign leads to higher resonant energy states. More pin numbers provide more surface distribution area to spread dipole charges which leads to worse charges alignment and redshift of dipole mode. However, as the pin number increases, the quadrupole surface charge was pushed toward the pin tip due to Coulomb repulsion. Better charge alignment caused the quadrupole blueshift. Other effects such as convex and concave shape and dielectric materials are also discussed. Our finding may provide a designing rule to synthesize multi-branch nanoparticles for bio-chemical sensing applications.

The circular dichroism (CD) performance of conjugated gammadion structure on the end facet of silicon waveguide in the mid-infrared regime is investigated theoretically. By engineering the orientation of the structure, the sign and value of its CD spectrum can be changed. For a fixed gammadion structure, different CD values can be obtained not only by changing the excitation wavelength but the excitation waveguide mode. This finding potentially provides an extra degree of freedom to design integrated chiral photonics chips.

Graphical abstractDisplay Omitted HighlightsThe intrinsic parameter fluctuation is studied for the 16-nm-gate TiN/HfO2 bulk FinFETs.The fluctuation includes the random discrete dopant, the random interface trap, and the random work function, simultaneously.The full 3D simulated threshold voltage fluctuation is 26.2mV for the N-type bulk FinFET.The statistical sum of these fluctuations is 9.5% overestimation because independence assumption on these random variables is invalid.Compared with the planar MOSFET, more than 50% reduction on the threshold voltage fluctuation is estimated. In this work, based on the experimentally calibrated 3D device simulation, we for the first time estimate the impact of intrinsic parameter fluctuation on the electrical characteristic of 16-nm-gate TiN/HfO2 bulk FinFETs. The sources of intrinsic parameter fluctuation include the random discrete dopants, interface traps and work function differences, simultaneously. The full 3D simulated threshold voltage fluctuation, induced by the aforementioned random sources simultaneously, is 26.2mV for the N-type bulk FinFET (and is 55.5mV for the planar N-MOSFET). For the N-type bulk FinFET, the statistical sum of these fluctuations is 9.5% (and is 12.3% for the planar device) overestimation, compared with the full 3D simulation. One of the main reasons is the independence assumption on these random variables is destroyed owing to interactions to different extents among RDs, ITs and WKs. The coupled surface potentials cannot be simply estimated by using their statistical sum of individual random source. Under the same threshold voltage, compared with the result of the planar MOSFETs, more than 50% reduction on the threshold voltage fluctuation of the explored bulk FinFETs is observed owing to the benefit of 3D structural nature.

In this paper, the dynamic characteristics of the novel amorphous silicon thin-film transistor gate drive circuit applied on a 10.1-in. panel are optimized by using a multi-objective optimization method. Simultaneously, considering the multiple electrical characteristics of the tested circuit, the achieved results reveal interesting properties as well as good sensitivity of the optimized design parameters. The optimal specifications not only suppress the output ripple, but also reduce the dynamic and static power consumptions.

In this study, effects of the thickness of a low temperature (LT) buffer and impurity incorporation on the characteristics of Nitrogen (N)-polar GaN are investigated. By using either a nitridation or thermal annealing step before the deposition of a LT buffer, three N-polar GaN samples with different thicknesses of LT buffer and different impurity incorporations are prepared. It is found that the sample with the thinnest LT buffer and a nitridation step proves to be the best in terms of a fewer impurity incorporations, strong PL intensity, fast mobility, small biaxial strain, and smooth surface. As the temperature increases at ~10 K, the apparent donor-acceptor-pair band is responsible for the decreasing integral intensity of the band-to-band emission peak. In addition, the thermal annealing of the sapphire substrates may cause more impurity incorporation around the HT-GaN/LT-GaN/sapphire interfacial regions, which in turn may result in a lower carrier mobility, larger biaxial strain, larger bandgap shift, and stronger yellow luminescence. By using a nitridation step, both a thinner LT buffer and less impurity incorporation are beneficial to obtaining a high quality N-polar GaN.

In this study, we investigated the effects of different heating processes on the structural, electrical and chemical properties of ZnO:Ga (GZO) films from the viewpoint of nucleation and growth behaviors. An infrared heating furnace and a traditional tube furnace were employed for the homogeneous and heterogeneous nucleation of GZO films. XRD patterns demonstrated that the preferential growth orientation of both kinds of GZO films is still the (002) direction. XPS data implied that the infrared heating process enables more uniform distribution of the dopant material and retards the oxidization of gallium in grain boundary areas. At the same time, the textured crystallite might provide a free tunnel for oxygen diffusion. Thus, the activation of free charge carriers could be more efficient when the GZO films were annealed under vacuum. As a result, the samples annealed by the infrared heating furnace had a noticeably high carrier concentration. Although the mobility was slightly smaller than that of the samples annealed by the tube furnace, film resistivity dropped obviously in general.

Using different precursor preparation, heating methods, and initial layers, this work investigated the relation between the micro-structural and electrical properties of ZnO:Al (AZO) films prepared by sol–gel method on glass and silicon substrates. It was found that adding monoethanolamine (MEA), using initial layers, or an intentionally produced steep temperature gradient obviously promoted film growth along the (002) direction. However, the carrier mobility rose only a little while the carrier concentration was not affected or even reduced. Generally speaking, the film conductivity was not evidently improved. It could be concluded that all three methods are advantageous for enhancing the crystallographic quality and therefore the mobility of the AZO films, but the major reason for the poor conductivity of the sol–gel derived ZnO films was the low activation of the dopant, which is the key factor for further improvements and should be solved first.

This paper introduces super absorbent polymer valves and colorimetric sensing reagents as enabling components of soft, skin-mounted microfluidic devices designed to capture, store, and chemically analyze sweat released from eccrine glands. The valving technology enables robust means for guiding the flow of sweat from an inlet location into a collection of isolated reservoirs, in a well-defined sequence. Analysis in these reservoirs involves a color responsive indicator of chloride concentration with a formulation tailored to offer stable operation with sensitivity optimized for the relevant physiological range. Evaluations on human subjects with comparisons against ex situ analysis illustrate the practical utility of these advances.

In this study, we investigated the influences of gallium concentration and a rapid thermal annealing process on the electrical and optical properties of ZnO:Ga (GZO) films prepared by sol–gel method. Experimental data indicated that the preferential growth directions of ZnO crystallites were the (002) and (103) axes. This phenomenon implied that the nucleation and growth behaviors of ZnO crystallites were changed by the infrared heating procedure and monoethanolamine. Furthermore, since the deposited sol films were heated simultaneously, evenly, and rapidly, dopant material Ga got the opportunity to replace Zn instead of forming oxides embedded in grain boundary areas. Thus, carrier concentration of the GZO films can be considerably enhanced while the mobility of the GZO films was not apparently affected in our experiments. It was also found that the carrier concentration was not sensitive to Ga/Zn ratio even though higher Ga concentration led to lower mobility. The best sample with a resistivity of 2.20 × 10−3 Ω cm and a transmittance of over 80% in visible region was achieved with 1.0 at.% Ga.

This study investigates the influences of the microstructures and doping effect on electrical and optical properties of ZnO:Al films deposited by sol–gel method. Experimental results showed that aluminum concentration affected the crystallite size obviously and enhanced the relative intensity i (002) faintly. Based on photoluminescence results, too much doping atoms generally can cause film crystallinity to deteriorate. Hall measurements indicated the carrier concentration rose only to a certain level after several coating processes. According to ellipsometric data, higher carrier mobility was mainly caused by the escalating density resulted by the increasing film thickness. However, the formation mechanism of charge carrier by doping technique in the sol–gel process is different from that of sputtering technique. The best sample having a sheet resistance of 182 Ω/sq and a transmittance of over 80% in visible region was obtained in aluminum concentration of 1.0 at.%.

Graphical abstractDisplay Omitted The HKMG Fin MOS device is fabricated with different interface between SiGe and SiO2.The interface roughness between the SiGe and SiO2 is extracted as a function of root mean square by analysis HRTEM.The interface roughness between the SiGe and SiO2 is modeled by corrected mobility model.Mobility of SiGe along (110) limits the total effective mobility on FinFET device.The interface roughness influences the mobility of SiGe. In this work, the FinFET HKMG MOS devices are fabricated on silicon wafer with p-substrate. The interface roughness between the SiGe and SiO2 is experimentally extracted and calculated as a function of root mean square by analysis of high resolution transmission electron microscopy. The surface-roughness dependent mobility model is then incorporated into device simulation to study the mobility of SiGe along (110) and (100) orientations of the devices. We further analyze four devices with different surface roughness along (100) and (100) orientations to demonstrate the influence of surface roughness on the total effective mobility.

In this paper, we estimate the influence of random dopants (RDs), interface traps (ITs), and random work functions (WKs) using the experimentally calibrated 3D device simulation on DC characteristic of high-κ / metal gate n- and p-type bulk fin-typed field-effect-transistors. We further study these intrinsic parameter fluctuations' impact on drain induced barrier lowering (DIBL). The main findings of this work show the RDF and WKF on n-type device are larger than that of p-type one. The DIBL is dominated by the number of random dopants.

In this work, the planar HKMG MOS devices are fabricated on (100) wafer with p-substrate. To improve the samples' interface roughness between the Si/Ge film and the interface layer, three different clean treatments are considered to fabricate the MOS devices. Among processes, the experiment indicates that HF and water rinse can present hydrogen termination to bond silicon as a good passivation. The measured C-V curves and HRTEM of the fabricated samples show the interface roughness is improved significantly. The extracted shift of flat band voltage (ΔVfb) and density of interface traps (Dit) have around 50% improvement.

The HKMG bulk FinFET has been one of major device technologies. However, the bulk FinFETs' characteristics has been affected to different extents by various fluctuation sources, such as random dopants (RDs), interface traps (ITs), work functions (WKs), and the process variations (PVs) [1-5]. In this work, we for the first time study the 16-nm-gate HKMG bulk FinFET's characteristic fluctuation resulting from the aforementioned random factors at the same time. By using an experimentally calibrated 3D quantum-corrected device simulation, the main findings of this study indicate the total Vth's fluctuation (σVth) of the tested device is 41.1 mV, where the RDs-induced σVth is the most serious one (28.5 mV) among all fluctuation sources. The coupled surface potentials cannot be simply estimated by using their statistical sum of individual random source.

Management of process variation and random fluctuation is one of severe challenges in scaling down silicon-based devices continuously according to Moore's law. Emerging fluctuation sources [1‒3] consists of the most critical random dopant fluctuation (RDF) which degrade device characteristic significantly. Unfortunately, recent studies on RDDs were reported for SOI FinFETs [1,5,8]. In this work, we for the first time statistically study characteristic fluctuation of 16-nm-gate high-к/metal gate (HKMG) bulk FinFETs with different aspect ratios (AR = 1 and 2; AR = H fin /W fin ) by random-discrete-dopants (RDDs) inside silicon fin channel, based upon our recent simulation studies [1–2,4–7]. Randomly generated devices with three-dimensional (3D) RDDs inside device channel is incorporated into quantum-mechanically corrected 3D device simulation. We compared the DC characteristics for planar and bulk FinFET devices. For the N-type bulk FinFET with AR = 2, it has higher I on and lower I off , further more the fluctuation of I on and I off are both smaller than the results of planar one, and the fluctuation of threshold voltage (σV th ) is 46.2 mV for the simulated N-MOSFETs which is significantly reduced to 22.9 mV for the bulk FinFET with AR = 2. We also discuss drain induced barrier lowering (DIBL) and subthreshold swing (S.S) for all devices, and the AR2 FinFET possesses the best performance no matter for the DIBL or S.S effects. There is 68.7% improvement on DIBL and 30.1% improvement on S.S from the planar [1,5,7–8] to AR2 FinFET. The findings of this study indicate that there is a relation between DIBL and RDD's position in which they are near or away from the silicon fin channel surface. It explains the different fluctuation magnitudes of the degraded DIBL effect on devices with the same number of RDDs.

In this work, we for the first time classify dopants that exist near the source/drain side or the upper/lower side of silicon fin and explore the impact of random dopants' (RDs) position on devices' DC characteristic. The effects of random dopant fluctuation (RDF) on the performance of 16–nm–gate HKMG bulk FinFET are studied by using experimentally validated three–dimensional RDF device simulation. The dopants near the source side or the upper fin would induce large barrier for electrons, so the threshold voltage (Vth) will be increased in n–type HKMG bulk FinFET devices which have more dopants on the source side or the upper fin. In addition, the upper–fin's dopants are discovered to have larger influence on the profile of energy band. Moreover, the issue about Vth's fluctuation on both the planar MOSFET and the bulk FinFETs with different aspect ratios (AR) is studied. The higher–AR HKMG bulk FinFET devices have relatively smaller Vth's variation induced by RDF.

In this paper, we, for the first time, study the metal gate's work-function-fluctuation-induced variability in the 16-nm-gate bulk and silicon on insulator (SOI) fin-type field effect transistor (FinFET) devices using an experimentally calibrated 3D device simulation. According to metal's property, random nanosized grains of titanium nitride (TiN) gate are statistically positioned in the gate region to examine the associated electrostatic potential and carrier transportation characteristics, concurrently capturing fluctuations resulting from nanosized grain's random number, position and size effects. The newly advanced methodology of localised work function fluctuation simulation enables us to estimate characteristic fluctuations and to examine the nanosized grain's random effects for the 16-nm-gate bulk and SOI FinFETs with TiN/HfO2 gate stacks with respect to the aspect ratio (AR = fin height/fin width) of two. The results of this study show that the DC characteristic fluctuation of FinFET devices strongly depends on the high and low work functions of localised nanosized metal grains. The threshold voltage (Vth) varies with the number of grain sizes and the Vth's fluctuation (σVth) is suppressed as the grain size is minimised. σVth of SOI FinFET (about 9.7 mV) is about 1.5 times smaller than that with bulk FinFET (about 14.6 mV). Furthermore, σVth of SOI FinFET with minimal metal grain's size of 2 × 2 nm2 can be reduced about 23%, compared with the result of bulk one.