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Oxide-based thin-film transistors (TFTs) with a lateral in-plane electrode are self-assembled on paper substrates, and the electrical modulation effect of the in-plane electrode is investigated. A \SiO2-based solid-electrolyte film with high specific capacitance is used as the gate dielectric, and the operation voltage is reduced to less than 2.0 V. The threshold voltage (Vth) of such paper TFTs is tuned from -0.98 to 0.94 V by different voltage biases on the in-plane electrode. The threshold voltage shift (\Delta Vth) can be described by \Delta Vth = -(CG2/CG1)VG2, where CG2 and CG1 are the in-plane electrode and bottom-gate specific capacitance values. High electrical performance with a current on/off ratio of \6 \times \10^5 \sim \10^6, a subthreshold swing of 0.14 \sim 0.19 V/dec, and a mobility of \8.64 \sim \9.45\ \cm^2/\V\cdot \s is obtained at different in-plane electrode voltage biases. Such low-voltage paper TFTs are promising for low-cost and portable electronics. [ABSTRACT FROM PUBLISHER]

An electrophoretic display (EPD) cell with a triple-layered microcavity structure was fabricated using a convenient dry film resist. The inherent structural advantage arising from the function of the middle channel layer as a background colored state enabled the EPD to operate with two different-colored states by using a single type of electronic-ink particles, thereby eliminating the possible agglomeration of oppositely charged ink particles and supporting the potential application of the proposed structure to color the electronic paper. The preliminary operation of this new EPD structure was demonstrated as white and blue display states on a rigid glass exhibiting a contrast ratio of 1.5 : 1 with saturation voltages of +30 and -30 V, respectively. Successful demonstrations on both the indium–tin–oxide-patterned glass and flexible polyethylene substrates are also provided. [ABSTRACT FROM AUTHOR]

This paper formulates the attitude filtering problem as a nonlinear stochastic filter problem evolved directly on the Special Orthogonal Group 3 (${\mathbb {SO}}(3)$). One of the traditional potential functions for nonlinear deterministic complimentary filters is studied and examined against angular velocity measurements corrupted with noise. This paper demonstrates that the careful selection of the attitude potential function allows to attenuate the noise associated with the angular velocity measurements and results into superior convergence properties of estimator and correction factor. The problem is formulated as a stochastic problem through mapping $ {\mathbb {SO}}(3)$ to Rodriguez vector parameterization. Two nonlinear stochastic complimentary filters are developed on $ {\mathbb {SO}}(3)$. The first stochastic filter is driven in the sense of Ito and the second one considers Stratonovich. The two proposed filters guarantee that errors in the Rodriguez vector and estimates are semi-globally uniformly ultimately bounded in mean square. Simulation results are presented to illustrate the effectiveness of the proposed filters considering high level of uncertainties in angular velocity as well as body-frame vector measurements. [ABSTRACT FROM AUTHOR]

In this paper, reliability issues of In2O5Sn (indium-tin oxide: a transparent material) transparent gate recessed channel (TGRC)-MOSFET has been analyzed by considering the effect of interface trap charges (both positive and negative) present at the Si/SiO2 interface. Following device, characteristics are studied in terms of static, linearity, and intermodulation figure of merits. It is found that with the amalgamation of the transparent gate indium tin oxide on conventional recesses channel (CRC) MOSFET, it exhibits improved immunity against interface trap charges in comparison to CRC-MOSFET. In addition, the influence of ambient temperature (150-300 K) along with trap charges on TGRC-MOSFET has also been explored with an aim to analyze at which temperature of the device is more stable in the presence of interface defects (trap charges). Results obtained reveal that TGRC shows improved device performance at low temperature with trap charges being less influenced. Thus, this paper demonstrates that TGRC MOSFET can act as a promising candidate for low-power linear analog applications, where low temperature is required. [ABSTRACT FROM AUTHOR]

This paper investigates the issues of oxygen accumulation and variation in the high-resistance state of HfO2-based resistive random access memory (RRAM), with improvement attained by inserting a thin oxygen-vacancy-rich layer of indium-tin-oxide (ITO) film. By acting as the oxygen ion reservoir, this ITO thin film on the TiN electrode can further stabilize resistance switching (RS) characteristics. In terms of reliability, ac endurance, and retention tests confirm stable RS characteristics for the Pt/HfO2/ITO/TiN device. Finally, a conducting model was proposed to explain the influence of the ITO thin layer and clarify the physical mechanism of electrical improvements. [ABSTRACT FROM AUTHOR]

In this paper, several fundamental pseudo-CMOS digital circuits with n-type indium tin oxide-stabilized ZnO thin-film transistors (TFTs) were implemented and investigated. The optical transmittance of circuits varied from 77% to 92% throughout the visible wavelength band. Electrically, the operation frequency of inverters, nor gates, nand gates, D latches, and D flip flops were all found to exceed 10 kHz with a supply voltage of 10 V. Besides, 13-stage ring oscillators could be operated at 42 kHz with a propagation delay time of $0.92~\mu \text{s}$ when the supply voltage was set as 20 V. Among the state-of-the-art transparent designs, these proposed circuits based on the ITO-stabilized ZnO TFTs exhibited high-speed performance, which were promising as building blocks for transparent electronics with moderate frequency requirements. [ABSTRACT FROM AUTHOR]

This paper proposes a design using a 2-D photonic crystal (PhC) structure-based thin film heterojunction GaAs solar cell with a periodic pattern extending from top transparent conducting oxide to inside the p-AlGaAs window layer placed just above the active layer of GaAs material. This paper presents the theoretical optical study and optimization of all the required parameters. This paper presents the optical optimization study for thin active layer cell in the generalized manner for 50-nm active layer, and then the performance of the proposed structure is compared with Lambertian limits and the planar cell, taken as reference. It has been predicted that these wavelength scale periodic structures greatly enhances the performance of the cell. The improvement in the performance is basically accounted for the better diffraction capability, impedance matching, trapping of high wavelength photons, and reduction in reflections from the top due to the PhC structure. The parameters have been optimized and calculated by means of rigorous coupled wave analysis. [ABSTRACT FROM AUTHOR]

In this paper, a detailed investigation of the realization of conformal wearable transparent antennas by integrating conductive mesh with polymer has been presented. The proposed realization method is much simpler and more cost-effective than the existing realization methods of transparent antennas, and the prototype fabricated from the selected composite materials is more flexible and robust in bending operations than other transparent antennas. In this paper, the mechanical, electrical, and optical characteristics of the proposed composite material have been investigated to analyze its suitability for transparent flexible antenna realization. For concept demonstration, a prototype of a dual-band antenna operating at 2.33–2.53 GHz and 4.7–5.6 GHz has been fabricated and tested. These frequencies cover both the instrument, scientific, and measurement (ISM) and the wireless local area network (WLAN) bands. Full ground plane is utilized in the antenna design for on-body operations. The suitability of the antenna for wearable applications has been investigated by measuring its performance under physical deformation and testing its performance on phantom. Next, the RF performance of the antenna has been improved by using two layers of conductor to form the radiating element. Although transparency is slightly compromised, the double-layer element improves the gain and efficiency of the antenna. [ABSTRACT FROM AUTHOR]

In contrast to the conventional planar p-i-n photodiode and a metal-semiconductor-metal photodetector, the 3-D dual-gate photosensitive thin-film transistor (TFT) architectures presented here attain excellent photoresponse characteristics. Operating the device in the subthreshold regime further boosts the photoconductive gain as a result of light-induced decrease in the threshold voltage. This paper presents design considerations along with a performance comparison between 3-D photosensitive TFTs that have π- and FIN-shaped channels and conventional TFT with a planar channel. Our paper shows that the π-shaped structure tends to have a higher sensitivity while the FIN-shaped counterpart is more responsive with wider dynamic range. For both structures, a measured photoconductive gain of 104~106% is obtained with spectral responsivity ranging from near UV to near IR, and the photoresponse time in the range of tens of milliseconds. The 3-D dual-gate photosensitive TFT architecture appears to be very promising for large-area, low-level UV, visible, and IR detection applications. [ABSTRACT FROM AUTHOR]

In this paper, we report the fabrication of flexible and transparent InGaZnO thin-film transistors on muscovite mica substrates. The mica substrate is compatible with four-step photolithographic processes as well as high-temperature processes. The field-effect mobility, subthreshold swing, ON/OFF ratio, threshold voltage, and hysteresis voltage are improved after annealing both at 300° C and 400° C in nitrogen. The device demonstrates more stable performance under positive gate bias stress when annealed at 400° C than at 300° C. The electrical performances are stable when exposed to tensile bending cycles up to 10 000 times. The mica with devices shows small optical loss in the visible region, where the average transmittance is as high as 86.75%. [ABSTRACT FROM AUTHOR]

Optically transparent planar antennas made of transparent conductive oxide (TCO) have attracted considerable attention in research over the years, particularly for solar panel applications. However, their design has proved difficult due to their inherent conductor losses. This paper focuses on the design of an optically transparent reflectarray using indium tin oxide, which is a type of TCO. The design is composed of subwavelength rectangular patch elements that exhibit 272° of phase range and mitigate conductor losses in reflectarray operation. This paper examines the behavior and response of lossy reflectarray unit cells and investigates different techniques to reduce the impact of loss in TCO reflectarray designs, primarily using different patch geometries and subwavelength elements. The proposed element design is simulated and experimentally characterized. A full reflectarray prototype operating at 26 GHz is successfully demonstrated and fabricated, with the simulated and experimental results in good agreement. [ABSTRACT FROM AUTHOR]

In this paper, a solar cell with amorphous silicon (a-Si) passivation that uses transition metal oxides (TMOs) for charge carrier collection has been modeled and analyzed for its performance. Charge carrier selection has been incorporated through selective band alignment provided by NiO and TiO2 TMOs for electrons and holes, respectively. The presence of a-Si interfacial layers for defect passivation prevents carrier loss due to high interface state densities at the Si/TMO interfaces. This structure is a potential candidate for high-efficiency solar cells (>25%) with a realistic approach towards the solution of high defect density. Optical analysis of the proposed structure has been done to analyze the amount of light entering the silicon and capable of generating electron–hole pairs. The amount of light lost has also been quantified into reflection loss, parasitic absorption, and back metal absorption. Impact of surface passivation quality and doping of NiO and TiO2 on its performance has been analyzed through the detailed device simulations. This provides a realistic pathway for engineering of passivation quality and doping of metal oxides for improved performance. [ABSTRACT FROM PUBLISHER]

In this paper, hybrid transparent conductive electrodes (TCEs) consisting of oblique-angle deposited indium tin oxide (OAD ITO) and silver nanowires (Ag NWs) were developed forGaN-based light-emitting diodes (LEDs). The 100-nm thick OAD ITO acted as an Ohmic contact to p-GaN with negligible light absorption having optical transmittance as high as approximately 99% at 450 nm, and Ag NWs acted as a favorable current spreader with sheet resistance as low as $19.9~\Omega $ /sq. Consequently, the hybrid TCEs consisting of OAD ITO and Ag NWs yielded an optical transmittance of 93% at 450 nm, a sheet resistance of 18.9 \Omega $ /sq, and a specific contact resistance of {2.1} \times {10}^{-2} \Omega \cdot cm2. LEDs fabricated with hybrid TCEs demonstrated improved electrical properties and greater optical output powers than the reference LEDs. This was due to the combined effects of the improved optical transparency, the enhanced current spreading, and the surface roughening effect. [ABSTRACT FROM PUBLISHER]

In this paper, for nonlinear stochastic systems, the optimal tracking control problem (OTCP) is solved by adaptive dynamic programming (ADP) techniques. Firstly, the complex OTCP is transformed into a stable control optimization problem by reconstructing a new stochastic augmented system. Then, simplifying the actor-critic architecture and reducing the computational load, critic neural networks (NNs) is used in iterative learning. And by using Lyapunov method, the ultimate uniform boundedness (UUB) of the tracking system is proved. To be precise, no literature has been published on the OTCP for nonlinear Itô type stochastic systems via the ADP method. This work is the first attempt in this field. Finally, in simulation, the method is applied to sinusoidal waveform and periodic rectangular step signal, and even unbounded exponential waveform. [ABSTRACT FROM AUTHOR]

A typical microwave oven generates an electromagnetic wave in an ISM band of 2.45 GHz. To prevent this unwanted microwave leakage through its front door, a circular perforated metal sheet is typically used with low shielding effectiveness (< 27 dB) and with poor visibility (< 50%) which is usually difficult to check the progress of cooking. In this paper, we investigate sheet resistance (RS) and optical transparency (OT) for electrical and optical performance of two transparent electrodes (TEs) including metal mesh film (MMF) and indium tin oxide (ITO) and compare those to the currently used perforated copper sheet (PCS) in commercial microwave oven. The measured RS and average OT in visible spectrum of MMF is 0.11 Ω/sq and 68.4%, and its figure of merit (FoM) is 203.8 which is the highest among them. The measured shielding effectiveness of MMF, ITO, and PCS at 2.45 GHz are 31.4, 21.0, and 25.5 dB, respectively. The results indicate that MMF has highest FoM and the best EMC performance among the TEs and PCS, which makes it the most suitable candidate for microwave ovens. [ABSTRACT FROM AUTHOR]

For the photovoltaic effect (PE), the surface potential is suggested to be an adverse factor, and researchers usually try to increase the thickness of the conductive layer or the number of strip electrodes to avoid it. However, the potential can still not be eliminated. More importantly, the huge cost has to be paid, and the photovoltaic performances are largely reduced. While the drawback of potential in PE may become excellent merit in lateral PE (LPE) due to their different working mechanisms. Moreover, the decreasing thickness of the conductive layer may be inversely used as an efficient method to modulate the LPE performances. In this paper, the indium tin oxide (ITO) conductive layer thickness-dependent LPE responses are well studied in the copper indium gallium selenide (CIGS) heterostructure. The LPE response is significantly improved with ITO thickness decreasing from 150 to 10 nm, and the thickness-dependent enhancement is strongly dependent on the illumination intensity, especially in high illumination intensities, a nonmonotonic thickness dependence is obtained. In addition, it is found that the heterostructure exhibits an ultrafast response speed of ~14.5 $\mu$ s/~15.0 $\mu$ s, and what is more, the response time nearly remains constant without depending on the ITO thickness. [ABSTRACT FROM AUTHOR]

In this paper, ZnO nanorod humidity sensors with dye-sensitized solar cells (DSCs) were prepared on indium tin oxide conductive glass. The average diameter and length of the ZnO nanorods were ~100 nm and $\sim 1.5~\mu \text{m}$ , respectively. After ZnO nanorods were grown, TiO2 film was coated by TiO2 with a nanoparticle size of approximately 26 nm through the doctor blade method. The sensitizer N3 was used for charge transfer on the DSCs. The solar photovoltaic conversion efficiency of the DSCs was approximately 4.7%. Humidity sensors were used for measurement under ultraviolet (UV) light at 365 nm. During UV illumination, the current increased under low humidity and gradually decreased under high humidity. The integrated device exhibited similar stable and sensitive performance as the traditional ZnO humidity sensor. Experimental results revealed that DSCs could be integrated with ZnO nanorod humidity sensors to create a self-powered integrated device that has potential Internet of Things applications. [ABSTRACT FROM AUTHOR]

In this paper, fully solution-processed organic solar cells were fabricated on prepurchased tin-doped indium oxide (ITO)-coated glass using the inverted architecture. Solution-processed electrodes consisting of ITO nanoparticle, silver (Ag) nanowire, or Ag nanoparticle films were used as the anode in the devices. Electrode deposition for solution-processed components was accomplished by using a commercially available airbrush with compressed dry nitrogen as the carrier gas. Morphologies of the deposited electrodes and the solution-processed electron blocking layer can be seen as topography images using atomic force microscopy. Cells fabricated with a solution-processed electrode show comparable device performances to that of an evaporated electrode using a similar structure. [ABSTRACT FROM AUTHOR]

In this paper, the power- and wavelength-dependent lateral photovoltaic effect (LPE) in an indium tin oxide/Si structure is first studied at different temperatures ranging from 292 to 80 K. It was found that the position sensitivity increased gradually until it became saturated with increasing laser power at a constant temperature, and the saturated position sensitivity increased nearly linearly from 2.47 to 3.91 mV/mm with increasing wavelength from 405 to 980 nm at 292 K. More importantly, the position sensitivity also increased considerably with decreasing temperature from 292 to 80 K, and the position sensitivity of 7.47 mV/mm at 80 K is about 1.91 times as large as that of 292 K under illumination of 70 mW for 980-nm laser. Based on the temperature-dependent Schottky barrier height, these results can be well explained. The significant observation of the improved LPE in infrared region makes this structure great potential in infrared position sensitive detectors, especially at low temperature. [ABSTRACT FROM AUTHOR]

This paper investigates material modifications induced by cosputtering indium-tin oxide (ITO) with gadolinium (Gd) at two different power levels. In addition, resistance switching (RS) properties were also verified for use as an insulator in resistive random access memory (RRAM). Comparison of scanning electron microscope (SEM) measurements for the two different cosputtering powers indicated significant changes of the ITO surface. Transparency was also verified by an N&K analyzer measurement, with results indicating a constant in transparency induced by the lower power Gd doping, indicating potential for transparent applications. Furthermore, the mole fraction ratio defined by X-ray photoelectron spectroscopy reveals a Gd2O3 peak, a likely reason for the ITO thin film becoming less conductive. This ITO/Gd:ITO/TiN RRAM can exhibit stable and robust RS characteristics at a lower forming voltage. In addition, lower operating voltages, including both SET and RESET voltages, can be obtained. Reliability tests including endurance and retention were carried out to confirm its RS stability. The RS mechanism of this ITO/Gd:ITO/TiN device was also investigated with the current–voltage (${I}$ – ${V}$) fitting method. Moreover, temperature effects were also applied to verify the high-resistance state (HRS) mechanism. Finally, a conduction model was proposed to clarify the RS characteristics and confirm that the ITO/Gd:ITO/TiN device is appropriate for data storage. [ABSTRACT FROM AUTHOR]

In this paper, the optical and electrical pulse responses of an optimized high-speed organic light-emitting diode (OLED) is investigated as a function of the pulse duration. The original design is based on the coplanar waveguide electrodes that are implemented on a transparent and conductive oxide thin film. The designed electrodes with reduced serial resistances (13 $\Omega $) allow to maximize the pulse energy delivery and to feed the organic device with short electrical pulses of few nanoseconds for the first time. This is achieved by designing the electrodes to have 50- $\Omega $ characteristic impedance, thanks to microwave techniques, and by implementing small values of capacitance (4.5 pF). The experimental results demonstrate $\boldsymbol \mu $ -OLED electrical and optical responses to electrical excitation pulses as short as 2.5 ns, for the first time, and state-of-the-art current densities above 1.7 kA/cm2. Moreover, and rather unexpectedly, the developed characterization procedure to extract the reported results demonstrated the first direct measurement of the electroluminescence lifetime of organic materials in the nanosecond time scale. [ABSTRACT FROM AUTHOR]

In this paper, we demonstrate a high-resolution $960\times 540$ blue-emitting active matrix micro-display. The blue micro-display have a diagonal length of 0.55 inch, a pixel size of $8~\mu \text{m}$ with a pixel pitch of $12.8~\mu \text{m}$ , and high pixel density of 2000 pixels per inch. The single pixel of micro-display exhibits excellent characteristics including an extremely low-leakage current of 0.1 pA at −5 V, a low forward voltage of 2.73 V, a narrow full width at half maximum of 15.7 nm of electroluminescence spectra, a high external quantum efficiency of 13.3%, and a deep-blue emission with CIE coordinates of (0.1589, 0.0542) at $11~\mu \text{A}$. Besides, the single pixel of micro-LED also shows high brightness of $4.2 \times 10^{6}$ and $7.4 \times 10^{6}$ cd/m2 at $500~\mu \text{A}$ and 1 mA, respectively. The complete $960\times 540$ micro-display has a contrast ratio of 3600000:1, the power consumption with all on is 0.5 W, and the pixel yield rate of about 98.674% analyzed by the software ImageJ. [ABSTRACT FROM AUTHOR]

The development of new sensing platforms could offer exciting opportunities for healthcare and environmental applications. In the last few decades, sensor device configurations have been limited owing to the use of electrochemical electrodes, resistors, and transistors. Capacitors are widely used for constructing various electronic devices. Here, we report for the first time the construction of a transparent interdigital transparent capacitor and its use for sensing ethanol. When the ethanol concentration changes, the dielectric properties of the capacitor change, resulting in the response of the impedance and capacitance. The capacitor shows a detection range of 0.1–1 volume fraction. It is expected that this paper could open up new opportunities for fundamental studies of more complex sensor configurations with a capacitor as one of the components and advance related healthcare and environmental applications. [ABSTRACT FROM AUTHOR]

Digital microfluidic biochips (DMFBs) are gaining increasing attention with promising applications for automating and miniaturizing laboratory procedures in biochemistry. In DMFBs, cross-contamination of droplets with different biomolecules is a major issue, which causes significant errors in bioassays. Washing operations are introduced to clean the cross-contamination spots. However, existing works have oversimplified assumptions on the washing behavior, which either assume infinite washing capacity, or ignore the routing conflicts between functional and washing droplets. This paper proposes the first integrated functional and washing droplet routing flow, which considers practical issues including the finite washing capacity constraint, and the routing conflicts between functional and washing droplets. Washing droplets of different sizes are also proposed to wash the congested cross-contamination spots. Effectiveness of the proposed method is validated by real-life biochemical applications. [ABSTRACT FROM AUTHOR]

We suggest functional passivation layers in the form of a distributed Bragg reflector (DBR) composed of ZnS and LiF for transparent thin-film transistors (TFTs) to improve the stability under negative bias illumination stress (NBIS). The luminous transmittance of the DBR was 82.0% when the number of dyads was 3.5, and the thicknesses of ZnS and LiF were 42 and 85 nm, respectively. We applied the DBR to TFTs based on amorphous indium-gallium-zinc oxide without the degradation of electrical performance, such as the mobility, ON–OFF ratio, subthreshold swing, and $V_{{\mathrm{\scriptscriptstyle ON}}}$ . The luminous transmittance of the TFT with the DBR was measured as 71.6%. $\Delta V_{{\mathrm{\scriptscriptstyle ON}}}$ of the TFT with the DBR was reduced to −1.119 V compared with that of the reference TFT, which is −3.261 V when a 1.25 MV/cm electric field was applied, and white light was illuminated during 3000 s. This confirms that the functional passivation layers suggested, in this paper, provide a solution to suppress the instability of TFTs in the NBIS and enhance the optical transmittance of transparent displays. [ABSTRACT FROM PUBLISHER]

Higher-order digital modulation formats are demonstrated by electrically inducing free-carrier concentration changes in thin films of transparent conducting oxides, integrated into well-established silicon-photonic waveguiding architectures. The proposed near-infrared modulators employ as physical platforms the silicon-rib and silicon-slot waveguides, exploiting the highly dispersive and carrier-dependent epsilon-near-zero behavior of transparent conducting oxides to modulate the optical carrier. Advancing the existing studies on conventional amplitude modulation, phase-shift keying formats are investigated in this paper, using a rigorous and physically consistent modeling framework that seamlessly combines solid-state physics with Maxwell wave theory through carrier-dependent material models. The designed in-line modulators achieve $V_\pi L$ products in the order of 0.1 Vmm, two orders of magnitude lower than their respective all-silicon or lithium niobate counterparts, accompanied by an insertion loss of about $3~\mathrm {dB/\pi }$. Switching speeds in the order of 50 GHz are feasible along with a potential for sub-pJ/symbol energy consumption, meeting the demands for on-chip optical modulation. [ABSTRACT FROM AUTHOR]

The development of a facile, low-temperature, and low-cost method to fabricate highly sensitive and optically transparent resistive pressure sensors remains a challenge. In this paper, a graphene/polyaniline-embedded polyvinyl butyral (GPANI-PVB) composite film is employed as the active layer in a resistive pressure sensor; this film is ultrathin, highly sensitive, optically transparent, anisotropically conductive, highly durable, highly flexible, and bending insensitive. A flexible touch panel based on the GPANI-PVB composite film is fabricated using a facile process, which supports multitouch and multilevel pressure detection. The GPANI-PVB composite film offers great potential for applications in flexible and transparent interactive electronic devices. [ABSTRACT FROM AUTHOR]

In this paper, we describe a capacitive micromachined ultrasonic transducer (CMUT) with improved transparency for photoacoustic imaging (PAI) with backside illumination. The CMUT was fabricated on a glass substrate with indium–tin oxide bottom electrodes. The plate was a 1.5- \mu \textm silicon layer formed over the glass cavities by anodic bonding, with a 1- \mu \textm silicon nitride passivation layer on top. The fabricated device shows approximately 30%–40% transmission in the wavelength range from 700 to 800 nm and approximately 40%–60% transmission in the wavelength range from 800 to 900 nm, which correspond to the wavelength range commonly used for in vivo PAI. The center frequency of the CMUT was 3.62 MHz in air and 1.4 MHz in immersion. Two preliminary PAI experiments were performed to demonstrate the imaging capability of the fabricated device. The first imaging target was a 0.7-mm diameter pencil lead in vegetable oil as a line target with a subwavelength cross section. A 2-mm-diameter single CMUT element with an optical fiber bundle attached to its backside was linearly scanned to reconstruct a 2-D cross-sectional PA image of the pencil lead. We investigated the spurious signals caused by the light absorption in the 1.5- \mu \textm silicon plate. For pencil lead as a strong absorber and also a strong reflector, the received echo signal due to the acoustic excitation generated by the absorption in silicon is approximately 30 dB lower than the received PA signal generated by the absorption in pencil lead at the wavelength of 830 nm. The second imaging target was a “loop-shape” polyethylene tube filled with indocyanine green solution ( 50~\mu \textM ) suspended using fishing lines in a tissue-mimicking material. We formed a 3-D volumetric image of the phantom by scanning the transducer in the $x$ - and $y$ -directions. The two experimental imaging results demonstrated that CMUTs with the proposed structure are promising for PAI with backside illumination. [ABSTRACT FROM AUTHOR]

A highly transparent resistive random access memory with a configuration of multilayer graphene (MLG)/ Dy2O3 /indium tin oxide (ITO) structure is demonstrated in this paper. The fabricated device is transparent, with 80% transmittance at 550 nm. The MLG/ Dy2O3 /ITO device shows unipolar resistance switching with a low operation current (<100~\muA) , low operation voltage (<1~V) , low power consumption (<100~\muW) , high resistance ratio (>10^4) , fast switching speed (<60~ns) , reliable data retention, and promising cycle endurance properties (>200~cycles) , which makes a step toward the realization of low-power transparent electronics for next-generation nonvolatile memory application. The MLG/ Dy2O3 /ITO device exhibited typical filamentary-conduction-type resistive random access memory behavior and no forming process is required. High resistance state (HRS) increases with a reduced device area while low resistance state (LRS) is insensitive to the device sizes. Moreover, Raman spectra obtained in pristine state, HRS, and LRS indicate that the lower power consumption of MLG/ Dy2O3 /ITO device is attributable to the formation of oxygen graphene layers. [ABSTRACT FROM AUTHOR]

MEMS biochemical sensors based on nanomechanical cantilevers (NMC) translate bio/chemical interactions into nanomechanical motion that can be detected by various transduction techniques. Polymer Nanomechanical Sensors have proven to be better candidates than the conventional silicon MEMS sensors owing to better sensor performance, ease of fabrication and cost effectiveness. In this paper, the development of novel polymer nanomechanical cantilever sensor platform with a high gauge factor Indium tin oxide (ITO) as piezoresistor for electrical transduction has been discussed. With simple and cost-effective polymer MEMS process integration, low temperature deposited ITO has been incorporated for efficient electromechanical transduction of SU-8 microcantilever devices. The fabricated SU-8/ITO microcantilevers were experimentally characterized for extracting the mechanical, electrical, and electromechanical properties. These SU-8/ITO devices exhibited strong negative piezoresistive behavior with the experimentally extracted gauge factor of ITO as −779. These devices show displacement sensitivity of 37 ppm/nm, which is nearly 30 times that of reported values of SU-8 cantilevers with nanocomposites as strain sensitive layer. The surface stress sensitivity is found to be 49.8 ppm [mN/m]−1. One of the potential applications of this polymer MEMS cantilever for room temperature detection of hydrogen gas has also been demonstrated. [2019-0266] [ABSTRACT FROM AUTHOR]

In this paper, the properties of hybrid-phase microstructural indium tin oxide-stabilized ZnO thin films and the relevant high-performance thin-film transistors (TFTs) were systematically investigated. The optically extracted Urbach energy revealed that such thin films owned less band-tail state trapping in comparison with that of the corresponding amorphous thin films. This was determined by better atomic arrangement and might realize higher drift mobility theoretically. The influence of deposition parameters such as oxygen partial pressure ratio (PO2) and direct-current power ( \textP\mathrm{ DC}) on thin films was discussed in detail. Then, the TFTs with optimal co-sputtering conditions were fabricated. Such devices exhibited a typical field-effect mobility of 26.1 cm2/ \textV\cdot \texts , threshold voltage of 0.5 V, on–off ratio of over 10^9 , and extremely low subthreshold swing of 89 mV/decade. Meanwhile, the spatial uniformity, air stability, and repeated switching behavior of devices were demonstrated to be excellent. [ABSTRACT FROM PUBLISHER]

This paper investigates the characteristics of applying indium–tin oxide (ITO) with and without nitride gas (N2) as the insulator in resistive random access memory (RRAM). After cosputtering an ITO target with N2 as the insulator and capping the same ITO material as the top electrode, the device exhibits rectifier and resistance switching characteristics before and after the forming process, respectively. The Schottky diodelike rectifier mechanism was also verified by various temperature measurements. Furthermore, robust resistance switching at a positive forming voltage, smaller than that required during negative bias forming, can be achieved. Both positive and negative forming processes are examined with current fitting results, which show different dominant mechanisms when using positive or negative biases. All these mechanisms have also been verified by temperature effect experiments, which confirmed the dominant conduction mechanisms. This, in combination with the fact that the positive forming voltage itself is smaller than the negative forming voltage, and decreases with device scale down, provides two highly beneficial results. This good performance achieved by using ITO with N2 suggests significant progress of RRAM and remarkable potential applications. [ABSTRACT FROM PUBLISHER]

This paper proposes low power consumption resistance random access memory (RRAM) devices with indium–tin-oxide (ITO) electrodes. The development of the Internet of Things (IoT) is a trend in future technology, but the bottleneck in IoT development is high power consumption; therefore, targeting low-power-consumption memory is crucial for the IoT. ITO-capped RRAM devices have been shown to exhibit outstanding performance and low power consumption, and here, we propose an oxygen accumulation mechanism by analyzing device characteristics. We find that the conduction current mechanism will be affected by oxygen absorbance in the ITO electrode. During the forming and set processes, oxygen ions will be propelled into the ITO electrode due to its oxygen vacancy-rich property; therefore, we find Schottky emission both at high-resistance state and low-resistance state and that the device exhibits an automatic current compliance property. Varied stop-voltage measurements were carried out to verify the device mechanism. Because of its capability for oxygen storage, the thick ITO layer was confirmed to affect the characteristic due to a difference in oxygen gradient. A new structure and novel material are proposed, based on the devices with ITO electrodes to improve performance and reduce power consumption. [ABSTRACT FROM PUBLISHER]

In this paper, indium-tin-oxide (ITO) was used to act as both insulator and top electrode in resistive random access memory (RRAM) on identical bottom substrates. This is achieved by cosputtering an ITO target with nitride (N2) or oxygen (O2) gas as the insulator; then capping by an ITO electrode, such that both the rectifier and RRAM characteristics can be achieved before and after a forming process, respectively. In contrast, using pure ITO as an insulator does not exhibit RRAM behavior. To verify the rectifier and RRAM characteristics, material analyses and electrical measurements at various temperatures were conducted. Reliability tests including retention and endurance were also applied to verify the resistance switching stability. Finally, the rectifier and RRAM conduction models were proposed to examine the resistance switching behaviors. By applying the ITO material as both electrode and insulator, the resistance switching characteristic with high reliability is thus obtained. [ABSTRACT FROM AUTHOR]

This paper proposes a new design module for reverse-connected microelectrochemical machining ( \mu-ECM), which is based on a novel electrochemical reaction that offers the fast removal of indium-tin-oxide (ITO) nanostructures from the surfaces of color filters in displays. Unlike general \mu-ECM models, the reverse-connected \mu-ECM model is implemented by connecting a workpiece to the cathode and an electrode to the anode of a dc power supply. During the course of machining, electrons travel from the cathode to the anode, so that the ITO film is lifted and removed at high speed by an electric field. In general \mu-ECM models, a workpiece is connected to the anode, an electrode is connected to the cathode, and the material removal is achieved by dissolution. In contrast, the reverse-connected \mu-ECM model provides higher removal efficiency and higher surface quality of color filters in displays during machining processes, thereby breaking new ground in superfine machining for applications in the photoelectric semiconductor industry. [ABSTRACT FROM AUTHOR]

This paper presented evaluation of electromagnetic (EM) energy absorption rate in terms of a specific absorption rate (SAR) in a fetus that was exposed to the EM wave from a portable radio terminal when used in the vicinity of the maternal abdomen. As for the numerical calculation, the electric fields around the antenna were analyzed by the finite-difference time-domain method. We considered analyzing six different positions of the antenna that are located around the waist. The SARs are normalized by 5-W radiated power from the antenna, which were a prevalent input power of wireless radio terminals in Japan. We confirmed that the SARs in the fetus are significantly affected by the distance and penetration path from the antenna to the surface on the fetus. Nonetheless, the SARs in the fetus are lower than the RF safety guidelines for occupational exposure in this paper. [ABSTRACT FROM AUTHOR]

This paper proposed a wireless real-time pH monitoring system. This system was associated ruthenium dioxide (RuO2) membrane pH sensor, microcontroller, liquid-crystal display (LCD), C/C++ program, and WiFi communication module to develop and use for ecosystem monitoring in the future. The ruthenium dioxide thin film of the pH sensor was deposited onto indium tin oxide (ITO) and polyethylene terephthalate (PET) substrates by the radio frequency (RF) sputtering system. The surface morphology of RuO2 thin film with scanning probe microscopy (SPM) was investigated. The electrochemical impedance analysis of RuO2 thin film was also studied. [ABSTRACT FROM AUTHOR]

In this paper, we construct a new suboptimal filter by deriving the Ito?s stochastic differential equations of the estimation of higher order central moments, satisfy, and impose some conditions to form a closed system. The essentially infinite-dimensional cubic sensor problem has been investigated in detail numerically to illustrate the reasonableness of the imposed conditions, and the numerical experiments support our discussion. A two-dimensional polynomial filtering problem has also been experimented. [ABSTRACT FROM PUBLISHER]

Inverted polymer solar cells (iPSCs) have shown a great potential in organic photovoltaics due to its enhanced stability and large-scale roll-to-roll processing. Metallated conjugated polymers also show promise as a donor material in the PSCs. In this paper, the role of solvents on the performance of inverted structure metallated PSCs was understood. Chlorobenzene (CB) and toluene were used as solvents to obtain the optimum morphology for improved device efficiency. To understand the charge transport properties and charge carrier lifetime in metallated polymer iPSCs, atomic force microscopy and transient photocurrent measurements were performed. The results showed that the CB as a solvent can improve the morphology of the active layer and enhance the performance of metallated iPSCs. [ABSTRACT FROM AUTHOR]

A high-performance microwave absorber with simultaneously ultra-broadband microwave absorption, mechanical flexibility and high optical transparency is proposed. A patterned indium–tin–oxide (ITO) conductive metasurface is used as the upper surface resonance layer. ANSYS HFSS 15.0 was used for the infinite period structures of the absorber simulation, and the Floquet port, master-slave boundary condition and adaptive meshing were set in the software. As a result, the absorber features >90% broadband absorption, which covers a wide frequency range of 17.6 GHz (21.6-39.2 GHz) and includes part of the K and Ka frequency bands. What is more, the absorption is above 99% in the range from 30 GHz to 33.6 GHz. The optical transmittance of the absorber in the visible light band is 85%. The thickness of the absorber is only 0.1 times of the wavelength corresponding to the lowest absorption frequency (13.89 mm). Furthermore, the absorber maintains stable absorption at different incident and polarization angles due to the quadruple centrosymmetric pattern. [ABSTRACT FROM AUTHOR]

Wind power has had a significant impact on power system stability due to its stochastic nature. In this paper, the impact of stochastic excitation on power-system small-signal stability is investigated based on stochastic differential equation (SDE) theory. The mechanical power input of an asynchronous wind turbine is considered as a stochastic excitation to the system and the system state equation is formulated based on SDE. The mean stability and mean square stability of such a system are demonstrated, and the steady-state expectation and covariance of the system state variables are obtained by mathematical deduction. The numerical simulations are presented on a two-machine infinite bus system and the IEEE 145-bus test system. [ABSTRACT FROM PUBLISHER]

We demonstrate the ink-jet printed fabrication technique for TiO2-based memristor, followed by detailed analysis of electrical characteristics and development of a new model that considers observed phenomena of quantized conductance steps. The existence of pinched hysteretic current–voltage characteristics is evidence of memristive behavior, provided by the reversible atomic rearrangement taking place in the functional layer. For the first time, performed electrical measurement on the micrometer thickness devices based on TiO2 active layer has captured the plateaux steps of the conductance at integer multiples of elementary quantum conductance. This behavior is consistent with the assumption that transport from electrode to electrode emerges through confined paths of conductive filaments with radius in the nanometer size range. Moreover, we introduce a novel model, based on the diffusion equation for ballistic transport in memristive devices, which considers the conductance plateaux steps. [ABSTRACT FROM AUTHOR]

We report a bidirectional, treated graphene oxide electrode-based organic bulk heterojunction solar cell. The nature of interfaces in the photoactive region (between PTB7/PC71BM), charge transport, and the role of treated graphene’s transparency in the device performance are investigated. Use of treated graphene reduces the sheet resistance (200–75 $\Omega$ /sq) of poly(3,4-ethylenedioxythiophene) polystyrene sulfonate thin film and improves the organic solar cell performance over a wide spectral range (250–750 nm). Due to: 1) the charge neutrality between PTB7 and PC71BM and 2) lowering of defect states in the electron collection layer, the overall solar cell power conversion efficiency ($\eta$) reaches 8.4% ± 0.23%; a fill factor of 69.5%, short-circuit current density of ${\sim} {16.1}\,\,\text {mA}\cdot \text {cm}^{-{2}}$ , and internal quantum efficiency of ~68.8%. [ABSTRACT FROM AUTHOR]

In this paper, we have newly developed a metal thin film-forming sputtering system using the Naturatron Sputtering method that can prevent the plastic film from suffering damage caused by the high-energy particles in plasma and carry out the low-temperature high-density metal deposition with a sputtering chamber and a film deposition chamber separated from each other. This system has made it possible to deposit the indium tin oxide (ITO) thin film on the poly(ethylene naphthalate) film as a substrate. As a result of energy-dispersive X-ray spectroscopy analysis or scanning electron microscope analysis performed for the ITO thin film, it has been proven that the uniform-surface ITO thin film can be deposited on a plastic film. [ABSTRACT FROM PUBLISHER]

This paper investigates how humans use a previewed target trajectory for control in tracking tasks with various controlled element dynamics. The human’s hypothesized “near” and “far” control mechanisms are first analyzed offline in simulations with a quasi-linear model. Second, human control behavior is quantified by fitting the same model to measurements from a human-in-the-loop experiment, where subjects tracked identical target trajectories with a pursuit and a preview display, each with gain, single-, and double-integrator controlled element dynamics. Results show that target-tracking performance improves with preview, primarily due to the far-viewpoint response, which allows humans to cancel their own and the controlled element’s lags, without additional control activity. The near-viewpoint response yields better target tracking at higher frequencies, but requires substantially more control activity. The control-theoretic approach adopted in this paper provides unique quantitative insights into human use of preview, which can help to explain human behavior observed in other preview control tasks, like driving. [ABSTRACT FROM PUBLISHER]

In this paper, the biocompatible/biodegradable materials, cellulose triacetate (CTA) and poly (lactic-co-glycolic acid) (PLGA), are used as dielectric layers in electrowetting-on-dielectrics (EWOD) devices. The mixture film has a relative dielectric constant of 6 by spin-coating and annealing at 100 ?C in oven for 30min. The porosity, unevenness and stability of electrowetting of the mixture film are studied. The results show its good property of film deposition and negative-potential sensitive electrowetting. Experiments of the EWOD device with 1.7 ?m CTA/PLGA demonstrate that water droplets can be driven and mixed successfully. This provides the potential realization of a complete biocompatible/biodegradable EWOD device. [ABSTRACT FROM PUBLISHER]

The dual-function glass dielectric resonator antenna (DRA) that simultaneously serves as a light cover is investigated for the first time. This paper is the first part, which demonstrates the idea using omnidirectional hollow rectangular glass DRAs. Both linearly polarized (LP) and circularly polarized (CP) designs are given. The glass DRA can generate CP fields by adding metallic patches onto its side walls, with a 3-dB axial ratio bandwidth of \sim 7\%. To obtain an entirely light-transmissible CP glass DRA, conducting indium tin oxide (ITO) patches are used in place of the metallic patches. For each of the LP and CP designs, powered light emitting diodes (LEDs) are placed inside the hollow region of the glass DRA to serve as the light source. It is shown that practically the lighting and antenna parts do not interfere with each other. The reflection coefficient, axial ratio (CP designs only), radiation patterns, and antenna gains of the proposed LP and CP antennas are studied, and good agreement between measured and simulated results is observed. [ABSTRACT FROM PUBLISHER]