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In this study, we propose a precise model of silicon tunneling field-effect transistors (TFETs) by modifying the Kane-Sze tunneling formula. In our model, a reference device is calibrated by utilizing TCAD and SPICE simulation. Electrical parameters extracted in our TCAD simulation are applied to a SPICE model not only for adopting the off-state current of a p-i-n diode under a reverse bias state but also for developing the threshold voltage and electric field equations. Furthermore, a basic complementary TFET inverter is simulated to demonstrate the capabilities of our proposed model.

In this study, we fabricate top-gate amorphous indium gallium zinc oxide (a-IGZO) thin-film transistors (TFTs) with five split channels on a bendable plastic substrate and investigate the electrical characteristics as a function of bending curvature radius. Owing to the channel width splitting effect, our TFTs have outstanding characteristics including a high mobility of 71.8cm2/Vźs and an on/off ratio of 108. Our bending study reveals that the operation regions of our TFT are categorized into safe, transition, and definitive mechanical failure regions as the value of the bending curvature radius decreases. In the transition region, the threshold voltage is shifted from 1.0 to 2.1V, and the mobility is decreased from 71.8 to 25.9cm2/Vźs. The electrical failure of bendable TFTs results from microcracks induced by mechanical strain. Display Omitted We fabricate bendable a-IGZO TFTs with five-split channels on a plastic substrate.The channel width splitting effect leads to the outstanding characteristics of TFT.We investigate electrical properties of a-IGZO TFT as a function of bending radius.We categorize the operations of TFT into three regions with the bending strain.

Display Omitted Si nanowires are fabricated by fully CMOS-compatible top-down route.Ring oscillator is fabricated on the polyethersulphone (PES) flexible substrate.We report a flexible ring oscillator which features 1-V operation.Ring oscillator generated a sinusoidal wave with a frequency of ~6.6MHz. In this study, we propose a flexible silicon nanowire (SiNW) low-power ring oscillator, which features 1-V operation. Our flexible ring oscillator is composed of three CMOS inverters with a gain of 70 at a supply voltage of 1V. p- and n-channel SiNW field-effect transistors (FETs) forming the component inverters exhibit on/off current ratios of 4.36×104 and 1.46×105, respectively. Our ring oscillator generates a sinusoidal wave with a frequency of ~6.6MHz. The frequency and waveform are undistorted under upwardly bent and downwardly bent strain conditions of 0.7%. The good mechanical bendability of the flexible ring oscillator indicates high stability and good fatigue properties.

We propose a simple route to examine the thermoelectric characteristics of Si nanowires (NWs) with infrared (IR) images in air. A device platform is designed to investigate the reliability of the thermoelectric characteristics. The Seebeck coefficients of the Si NWs obtained from all the electrode-couples in the platform are nearly identical at about [email protected]/K, revealing the validity of the simple route. The directly measured Seebeck voltages are carefully compared with the sum of the individual Seebeck voltages, and the comparison is discussed in detail.

In this study, resistive random access memory (ReRAM) devices are fabricated using solution-processable sulfur-doped GeO"2 (GeO"2:S) on flexible substrates. The Al/GeO"2:S/Au ReRAM devices exhibit the unipolar resistive switching behavior with an on/off ratio of more than 10^7 and the memory characteristics are retained after 10^4s. The memory characteristics are unaffected by strains, even after the continuous substrate bending test for 10^3cycles.

We demonstrate bottom-gate thin-film transistors (TFTs) based on solution-processed HgSe nanocrystals (NCs) on plastic substrates. Solid films made of spin-coated HgSe NCs were heated at a temperature of 150^oC for 15min to maximize the magnitude of their current, and these films were utilized as the channel layers of TFTs. A representative TFT with a bottom-gate Al"2O"3 layer operated as a depletion-mode one with an n-channel, exhibiting a field effect mobility of 3.9cm^2/Vs and an on/off current ratio of about 10^2. In addition, the electrical characteristics of the TFT on bent substrates are briefly described.

In this study, top-gate ZnO nanowire field-effect transistors (FETs) were successfully fabricated using a photolithography process, and their electrical properties were characterized by I-V measurements. Their electrical characteristics were compared with those of back-gate ZnO nanowire FETs. The fabricated nanowire FETs exhibit good contact between the ZnO nanowire channels and Ti metal electrodes. A representative top-gate FET showed a higher gate dependence than a representative back-gate FET; the peak transconductances of the back- and top-gate FETs were 19nS and 248nS, respectively. These characteristics reveal that the top-gate nanowire FET fabricated by the photolithography process has better performance. The fabrication technique used for the nanowire FETs by a photolithography process in this study is applicable to the fabrication of various devices including TFTs, memory devices, photodetectors, and so on.

Electrical characteristics of field-effect thin-film transistors (TFTs) with p-channels composed of CdTe/CdHgTe core-shell nanocrystals are investigated in this work. For the fabrication of bottom- and top-gate TFTs, CdTe/CdHgTe core-shell nanocrystals synthesized by the colloidal method are first dispersed on oxidized p^+ Si substrates by spin-coating, the dispersed nanocrystals are sintered at 150^oC to form the channels for the TFTs, and Al"2O"3 layers are deposited on the channels. A representative bottom-gate field-effect TFT with a bottom-gate SiO"2 layer exhibits a mobility of 0.21cm^2/Vs and an I"o"n/I"o"f"f ratio of 1.5x10^2, and a representative top-gate field-effect TFT with a top-gate Al"2O"3 layer provides a field-effect mobility of 0.026cm^2/Vs and an I"o"n/I"o"f"f ratio of 2.5x10^2. The CdTe/CdHgTe nanocrystal-based TFTs with bottom- and top-gate geometries are compared in this paper.

The capacitance characteristics of aluminum nanocrystal-embedded metal-oxide-semiconductor (MOS) capacitors with gate layers composed of Al"2O"3 layers are investigated in this work. The capacitance versus voltage (C-V) curves obtained from a representative MOS capacitor embedded with aluminum nanocrystals synthesized by the thermal treatment process exhibit the window of flat-band voltage shift, which indicates the presence of charge storages in the aluminum nanocrystals. Their hysteresis curves are dependent on the range of sweep voltage. The counterclockwise hysteresis and leftward shift of the flat-band voltages observed from the C-V curves signify that electrons are trapped in a floating gate layer consisting of the aluminum nanocrystals present between two Al"2O"3 layers in the MOS capacitor, and that these trapped electrons originate from the p-type Si substrate.

In this study, we characterize multilevel bipolar switching in devices composed of Au/ZnO/ITO constructed on glass. The ratio of the measured resistance in the low-resistance state (LRS) to that in the high-resistance state (HRS) depends on the starting sweep voltage. The HRS/LRS ratio increases from 10 to 10^4 as the starting sweep voltage changes from -1 to -3.5V. Moreover, the Au/ZnO/ITO devices can complete more than 10^2 cycles and maintain their characteristics for up to 10years. A more detailed description on the multilevel bipolar switching of our devices will be given in this paper.

In this study, enzyme-free glucose sensors with channels composed of necked zinc oxide (ZnO) nanoparticles (NPs) are constructed on a plastic substrate, and their sensing characteristics are examined. When a phosphate buffer solution (PBS) of lower pH than the isoelectric point of ZnO is adsorbed on the necked ZnO NP channels, the current increases remarkably in magnitude at a bias voltage of 10V compared with ZnO NP channels without the adsorption of PBS. The current decreases in magnitude with increasing number of moles of added glucose. When 2.5x10^-^1^2 moles of glucose are adsorbed on the PBS-adsorbed channels, the current in the channels at 10V decreases in magnitude from [email protected] to 600nA. The enzyme-free glucose sensors can detect 5x10^-^1^3 moles of glucose in air at room temperature.