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A thin‐film transistors (TFTs) integrated gate driver circuit with bifunctional capacitors for in‐cell touch with horizontal blanking display mode is proposed in this paper. The coupling capacitor, which conventionally enables low‐level‐maintaining parts in display periods, is reused to store transfer charges during touch detection periods. Consequently, only nine TFTs and two capacitors are used for a single stage of the proposed gate driver for in‐cell touch display. Furthermore, the bifunctional capacitor scheme not only avoids the driving TFT from long‐time voltage stress but also suppresses the transfer charges leakage effectively. Therefore, the variation ratios of rising/falling time between adjacent gate driver stages are suppressed within 6%. For a 5.7‐in. display with HD+ resolution, the layout of a single gate driver stage is 623 μm (width) × 171 μm (height). The proposed gate driver circuit has been prepared with the state‐of‐the‐art hydrogenated amorphous silicon (a‐Si:H) TFT manufacturing process. The measured results verified the circuit functions. The gate driver output waveforms are well maintained and being almost independent of touch detection time interval from 100 to 300 μs. [ABSTRACT FROM AUTHOR]

In this work, a dual-sided buffer template, which allows the deposition of YB 2 Cu 3 O 7-δ (YBCO) coated conductors on both sides, has been proposed and investigated. Theoretically, in contrast to traditional YBCO structure on one side, the performance of critical current in YBCO films has been improved by two times. In this buffer structure, the dual-sided Y 2 O 3 films were grown on a flexible metal template by a home-made reel-to-reel dynamic direct current sputtering system and the film growth parameters were systematically investigated. The microstructure were characterized by in situ reflection high-energy electron diffraction monitoring in real time during the deposition stage. X-ray diffraction, and atomic force microscopy were used to detect the biaxial texture and surface morphology, respectively. What's more, by the application of stopping and range of ions in matter software, it helped us to understand the influence of deposition parameter to the growth rate of Y 2 O 3 films. Finally, the biaxial texture of dual-sided Y 2 O 3 film yielded out-of-plane texture of Δ ω = 4.2° and in-plane texture of Δ Φ = 5.2° for one side, as well as Δ ω = 5° and Δ Φ = 5.3° for the second side. Subsequently, the dual-sided YBCO superconducting films were coated on the above Y 2 O 3 buffer layer by low-cost metal-organic chemical vapor deposition method with critical current of 30 A/cm and 60 A/cm for each side. [ABSTRACT FROM AUTHOR]

A new pixel circuit is proposed for the realization of high resolution and high uniformity organic light-emitting diode on silicon (OLEDoS) microdisplays in this article. A compensation scheme is adopted to mitigate the influence of threshold voltage variation of the driving transistor on display uniformity. Furthermore, two coupling capacitors are used to reduce the voltage at the gate terminal of the driving transistor in order to extend the data voltage range. The performance of the proposed pixel circuit is verified in an industrial 0.18- $\mu \text{m}$ CMOS process. Simulation results show that the data voltage of the proposed pixel circuit ranges from 0.5 to 3.12 V, which is up to $4.37\times $ wider than the previously published pixel circuits. The emission current error of the proposed pixel circuit varies from −2.1% to 2.08%, under the condition of ±5 mV threshold voltage variation for the driving transistor. The maximum emission current error changes from −10.36% to −2.62% when the OLED turn-on voltage is increased by 5 to 20 mV due to device aging. Furthermore, the proposed pixel circuit only occupies a layout area of $8.1\,\,\mu \text{m}\,\,\times {4}\,\,\mu \text{m}$. [ABSTRACT FROM AUTHOR]

A hydrogenated amorphous silicon (a-Si:H) thin-film transistor (TFT) gate driver on array with low-level holding TFTs (LLH TFTs) biased under bipolar pulse is investigated. It is shown that the bipolar bias at low frequency significantly alleviates the threshold voltage shift of the LLH TFTs. As a result, the lifetime of the proposed gate driver is demonstrated to be several times of that under the conventional unipolar pulse bias. In addition, the improvement in the lifetime becomes more significant at the higher work temperature. The liquid crystal display television panels (32-in, 1366\times \textrm RGB\times 768 ) with the proposed a-Si:H gate drivers integrated on array are manufactured, and the feasibility of the proposed driving scheme is well verified. [ABSTRACT FROM PUBLISHER]

An integrated five-transistor/one-capacitor approach for realizing a a-Si:H thin-film transistor (TFT) gate driver operating in multiphase-clock mode is proposed and investigated. The driver needs only one large-size TFT and one small-size storage capacitor. The performance and function of the proposed driver are verified experimentally. The dependence of the performance on the device size is studied in detail. Stability of the fabricated drivers is tested using a flexible measurement scheme. Measured results show that the fabricated gate driver can work stably even though the low-level-holding TFTs have a threshold-voltage shift of 19 V. [ABSTRACT FROM AUTHOR]

A peak-voltage detection circuit based on a differential comparison structure is proposed to synchronize the control and the input signal. The detection circuit is hence free of reset signals for the sampling capacitors. Furthermore, a two-channel parallel sample and hold structure (i.e., S/H circuit) is used, and a correlated double sampling technique is used, in combination with the ping-pong technique, to sample the signal value and offset voltage within one sample cycle. Consequently, the parallel connected S/H structure can not only extract the offset voltage of the op-amp but also effectively reduce the detection error, which is caused by circuit noise and leakage current. Measurements of the implemented peak detector show that in the case that the detection signal frequency is 20 kHz and the amplitude is 10 mV, the detection error is decreased to 30 µV with the equivalent output noise of 71 n V / H z . [ABSTRACT FROM AUTHOR]

• Dynamic current hysteresis that can well capture the effect of the trap energy level, trap density and scan rate is proposed. • This Dynamic current hysteresis model based on trap kinetics is well compatible with SPICE simulations. • The methodology of this hysteresis model can be well extended to other trap kinetics theory and emerging devices. This paper proposes a dynamic current hysteresis model for the Indium Gallium Zinc Oxide Thin Film Transistor (IGZO-TFT). Based on the Shockley-Read-Hall (SRH) theory, a kinetic equation that accurately describes the interface trap's capture/emission behaviour is presented, which can incorporate the effect of interface trap density, trap energy level and scan rate dependency. Further, the kinetic equation is solved using a sub-circuit approach, combined with a calibrated TFT static current model, to achieve an accurate simulation of the current hysteresis of IGZO-TFT. This model has been validated with numerical TCAD simulations and has been shown to precisely reflect the effect of trap energy level, trap density and scan rate on the current hysteresis characteristics. [ABSTRACT FROM AUTHOR]

Threshold voltage shift ( \Delta V\mathrm{ TH} ) effect of hydrogenated amorphous silicon thin-film transistors under bipolar pulse bias stress (BPBS) is investigated. The dependence of the \Delta V\mathrm{ TH} effect on the signal pulsewidth, stress temperature, and negative pulse voltage magnitude of the BPBS is systematically measured, and explained by the charge trapping and detrapping theory. Results show that the BPBS leads to a noticeably suppressed \Delta V\mathrm{ TH} , compared with the conventional unipolar pulse bias stress. It is suggested that the BPBS with proper negative pulse voltage magnitude and low pulse frequency is an effective way of suppressing \Delta V\mathrm{ TH} , especially when the thin-film transistors work relatively at high temperature. [ABSTRACT FROM PUBLISHER]

The microwave dielectric behavior of sandwich-like Ti3C2 MXene nanosheets with efficient microwave absorption was investigated by a combination of experiments and simulations. The obvious frequency dispersion effect and the double-peaked feature of dielectric spectra in Ti3C2 MXene nanosheets could be observed over the frequency range of 2–18 GHz, giving rise to superior microwave attenuation capability. Furthermore, a revised Drude-Lorentz model was proposed to explain the peaked feature of permittivity, and simulated results were demonstrated to agree well with the experimental measurements. It was concluded that the hopping migration between Ti3C2 MXene nanosheets with longer relaxation time than “micro-dipole” relaxation within nanosheets makes a superior contribution to overall absorbing performance. [ABSTRACT FROM AUTHOR]

For large-area electronic applications, the mechanism of the leakage current in oxide-semiconductor thin-film transistors (TFTs) has become a critical issue. In this work, the impact of the irradiation location on the photo-leakage current of zinc oxide (ZnO) TFTs is investigated. The photo-leakage current of the ZnO TFTs is not only dependent on the light irradiation but it is also dependent on the parasitic capacitance between the drain electrode and the floating gate metal. The photo-leakage current of the source-half irradiation TFT is larger than that of the drain-half irradiation TFT. To explain this phenomenon, the profile of the electric potential and the electron concentration is analyzed by two-dimensional device simulation. It is found that the floating gate metal plays the dominant role in the photo-leakage current. This research provides insight into TFT structure optimization and high-performance TFT process development. [ABSTRACT FROM AUTHOR]

This paper presents a proposed capacitance readout circuit that enables a quadrupled (x4) output strength. A symmetric cross-coupling structure is proposed to amplify the voltage difference between two adjacent channels; hence, the detected signal can be integrated twice every clock cycle. Compared with conventional schematics, the proposed readout circuit shows an increased output strength for integration times within dozens of μs. In addition, the measurements show that the integrator resistors should be less than 1 kΩ to suppress the resistance–capacitance delay effects. Although the proposed capacitance readout circuit is implemented using discrete transistors, it has a good signal integrity at an operating clock cycle of 100 µs. Therefore, the proposed readout circuit is a promising way to detect small capacitance variations with short integration times. [ABSTRACT FROM AUTHOR]

• The infrared emissivity presents periodical fluctuation phenomenon along edge length. • The peaked frequency is inclined to shift towards lower region with area ratio increased. • There exists intrinsic attenuation which is probably attributed to the diffuse scattering. Composites or structures with adequate infrared reflection and microwave transmission are favorable from practical point of view. In this paper, oriented flaky aluminum filled pyramidal-frustum shaped periodic coatings was developed, and the effect of area of flaky aluminum powder filled coating on the infrared emissivity as well as microwave transmission behavior was intensively studied combined experiments with simulation. Results shown that the increments of oriented flaky aluminum filled coating could effectively reduce infrared emissivity. After spraying flaky aluminum filled periodic structures on the microwave absorbing material, the frequency corresponding to minimal reflection loss is inclined to shift towards lower frequency. Numerical simulation results shown that reflection coefficient gradually increases with increasing in frequency and area ratio of flaky aluminum filled coating. Besides, there exists intrinsic attenuation of flaky aluminum filled pyramidal-frustum shaped periodic coating, which is probably attributed to the diffuse scattering within step edge region. [ABSTRACT FROM AUTHOR]

Though impressive advances of the extension of effective working distance for magnetic resonant coupling wireless power transfer system have been made over past decades, their applications have been severely limited by the requirement of unidirectional coaxial distribution for the transmitter and receiver. In this paper, an omnidirectional magnetic resonant coupling wireless power transfer system is proposed. The cubic spiral transmitter requires only a single power source, and the receiver receives power in all directions. The power transfer efficiency of the system is derived through an equivalent circuit model. And an impedance matching circuit which includes a pair of parallel and series capacitors is proposed for better stability and higher efficiency. In addition, geometrical parameters of the single power driven spiral transmitter structure are optimized to improve distribution uniformity for different directions. Thus the power transfer efficiency of the system, which depends on the distance between the transmitter and the receiver, is almost the same for different receiving angles. Finally, the theoretical analysis is verified by practical experimental results, which shows the power transfer efficiency of 60% at 150 mm. [ABSTRACT FROM AUTHOR]

Biphase particulate magnetoelectric ceramics (1- x )Bi 0.5 Na 0.5 TiO 3 - x La 0.67 Sr 0.33 MnO 3 ( x  = 0.05, 0.15, 0.25 and 0.35) were prepared using the powder-in-sol precursor hybrid method. Effect of magnetic field on polarization response in composites was studied, by analyzing the magnetodielectric effect and ferroelectric loops under the applied magnetic field. The switching of magnetodielectric effect and the variation ferroelectric polarization is mainly determined by the competitive mechanisms of magnetoresistance and magnetostriction. Furthermore, the direct magnetoelectric output was carried out and the maximum ME voltage coefficient reached up to 19.1 mV/cm·Oe for the x  = 0.15 composite. [ABSTRACT FROM AUTHOR]

The electrochromic (EC) process is essentially an electrochemical reaction associated with the intercalation (de-intercalation) of ions to (from) the EC film. To improve the infrared emissivity modulation performances of the infrared electrochromic devices (IR-ECDs), polyaniline/carbon quantum dots (PANI/CDs) flexible films were fabricated by the electropolymerized approach in this paper. The prepared PANI/CDs porous films were exhibited and verified excellent electrochromic properties through micromorphology analysis and electrochemical tests. The measured emittance variation (Δ ε) of the prepared PANI/CDs samples are 0.41, 0.46, and 0.42 in ranges of wavelength 3–5 μm, 8–14 μm, and 2.5–25 μm, respectively. In addition, for the infrared range of 2.5–25 μm, the radiation energy can be continuously modulated from 80.77 to 241.98 W/m2 (ΔP = 161.21 W/m2). The assembled IR-ECD based on PANI/CDs films obtains excellent IR modulation ability, that the emittance variations are 0.39, 0.41, and 0.37 in the wavelength ranges of 3–5 μm, 8–14 μm, and 2.5–25 μm, respectively. The switching times of the device for the coloration and bleaching are 3.1 s and 3.7 s respectively, much shorter than that of previously reported ECDs based on PANI. Meanwhile, the developed ECD presents decent durability, as the Δε values of IR-ECD in wavelength ranges of 3–5 μm, 8–14 μm, and 2.5–25 μm maintaining radio of 75%, 76%, and 68%, and current maintaining ratio of the device is above 90% after aging measurements of consecutive 100 cycles. Furthermore, the integrated IR-ECD was proposed to achieve dynamic conversion from golden yellow to dark green in the visible light regime through precise tuning of external biasing voltage. The proposed ECD based on PANI/CDs technology is promising for the future of adaptive IR sensors and thermoregulation-related applications. [Display omitted] • The high electrochromic performance devices based on PANI/CDs porous films were prepared by the electropolymerized method. • The flexible films based on PANI/CDs exhibit enhanced electrochemical performance by doping the carbon quantum dots. • The infrared-electrochromic device exhibits the strong IR modulation ability, fast response time, and excellent stability. • A novel integrated infrared-electrochromic device was proposed to reduce the external driving signal lines. [ABSTRACT FROM AUTHOR]

A dual-gate (DG) amorphous indium–gallium–zinc-oxide thin-film transistor (TFT)-driven pixel circuit for active-matrix organic light-emitting diode displays is presented. One gate of the DGs serves as a primary gate (PG) and the other as an auxiliary gate (AG). The threshold voltage ( V\mathrm {{TH}} ) of the DG TFT under the PG operation is modulated by the AG bias voltage. The V\mathrm {{TH}} variation ( \Delta V\mathrm {{TH}} ) is compensated with the AG and the drain diode-connected structure. The validity of the presented pixel circuit is experimentally verified. The measured current error rates are less than 3.2% at a \Delta V\mathrm {{TH}} of \text TFT = \pm 0.5 V and a \Delta V\mathrm {{TH}} of OLED = 0.5 V with the emission current ranging from 7 nA to 1.13~\mu \textA . [ABSTRACT FROM AUTHOR]

An optically transparent metamaterial absorber (MMA) operated in the C-band (4–8 GHz) is optimally designed based on the second-order cross fractal structure. The experimental results show that the reflection loss of the proposed MMA is lower than −10 dB from 3.98 GHz to 8.68 GHz. Two overlapped resonances located at 4.77 GHz and 7.33 GHz, respectively, are caused by the second-order cross fractal structure. Distributions of surface current, electromagnetic field and power loss density are investigated to illustrate the absorptive characteristics and electromagnetic loss mechanisms of the proposed MMA. Moreover, the average optical transmittance of the MMA is close to 75% from 390 nm to 780 nm. The MMA possesses simultaneously strong absorptive capacity in the C-band and high transmittance in the visible light range, showing potential application in special environment. • The designed metamaterial absorber with second-order cross structure shows strong microwave absorption and good optical transmittance. • The reflection loss is lower than -10dB in 3.98~8.68 GHz range. • The average optical transmittance is about 75% in 390~780 nm range. [ABSTRACT FROM AUTHOR]

In this paper, a new metamaterials-based hypersensitized liquid sensor integrating omega-shaped resonator with microstrip transmission line is proposed. Microwave transmission responses to industrial energy-based liquids are investigated intensively from both numerical and experimental point of view. Simulation results concerning three-dimensional electromagnetic fields have shown that the transmission coefficient of the resonator could be monitored by the magnetic coupling between the transmission line and omega resonator. This sensor structure has been examined by methanol–water and ethanol–water mixtures. Moreover, the designed sensor is demonstrated to be very sensitive for identifying clean and waste transformer oils. A linear response characteristic of shifting the resonance frequency upon the increment of chemical contents/concentrations or changing the oil condition is observed. In addition to the high agreement of transmission coefficients (S21) between simulations and experiments, obvious resonant-frequency shift of transmission spectrum is recognized for typical pure chemical liquids (i.e., PEG 300, isopropyl alcohol, PEG1500, ammonia, and water), giving rise to identify the type and concentration of the chemical liquids. The novelty of the work is to utilize Q factor and minimum value of S21 as sensing agent in the proposed structure, which are seen to be well compatible at different frequencies ranging from 1–20 GHz. This metamaterial integrated transmission line-based sensor is considered to be promising candidate for precise detection of fluidics and for applications in the field of medicine and chemistry. [ABSTRACT FROM AUTHOR]

A precision bandgap reference (BGR) with high power supply ripple rejection (PSRR) and low temperature coefficient (TC) is proposed for the peripheral compensation circuitry of active-matrix organic light-emitting diode (AMOLED) displays. The PSRR is enhanced by a coupling structure of the power supply and a feedback loop of the start-up circuit. Furthermore, a high-order nonlinear compensation method is proposed to reduce the temperature coefficient by utilizing the systematic nonlinear offset voltage within the bandgap circuit. Measurement results of the proposed BGR implemented in an industrial 0.25-μm CMOS process demonstrate a TC of 4.99 ​ppm/°C in a wide temperature range of −40 ​°C–130 ​°C. A PSRR around −80 dB is also achieved by the proposed circuit at low frequency. [ABSTRACT FROM AUTHOR]