Surmounting Erase-Operation Limit in Organic Charge-Trap Memories by Fine Tuning Electron Injection at Semiconductor/Heterobimetallic Electrode Contacts.

Heterobimetallic systems (HBS), known for their ability to facilitate the versatile design of surface workfunctions, offer significant potential as an electron-injection electrode layer for organic semiconductors. In this paper, we propose a universal and effective strategy to overcome the limitations of the erase operation in charge-trap memory with a small-bandgap organic semiconductor or diketopyrrolopyrrole-quaterthiophene-conjugated polymer (PDPP4T) by utilizing HBS-based source/drain (SD) electrodes. Conventional gold SD electrodes restrict electron injection into the PDPP4T layer during the electrical erase operation and impose a lower limit on the erasing voltage required for full threshold-voltage recovery.

Effect of Gate Bias Stress on the Electrical Characteristics of Ferroelectric Oxide Thin-Film Transistors with Poly(Vinylidenefluoride-Trifluoroethylene).

We investigated the effect of gate bias stress (GBS) on the electrical characteristics of ferroelectric oxide thin-film transistors (FeOxTFTs) with poly(vinylidenefluoride-trifluoroethylene). Generally, conventional oxide thin-film transistors (OxTFTs) with dielectric gate insulators exhibit a small negative shift under negative gate bias stress (NBS) and a large positive shift under positive gate bias stress (PBS) in transfer characteristic curves. In contrast, the FeOxTFTs show a small positive shift and a large negative shift under NBS and PBS, respectively.

A Dew-Condensation Sensor Exploiting Local Variations in the Relative Refractive Index on the Dew-Friendly Surface of a Waveguide.

We propose a sensor technology for detecting dew condensation, which exploits a variation in the relative refractive index on the dew-friendly surface of an optical waveguide. The dew-condensation sensor is composed of a laser, waveguide, medium (i.e.

Investigation on the Electrical Stability of 5,11-Bis(triethylsilylethynyl)anthradithiophene Thin-Film Transistors.

We investigate the effects of environmental conditions on the electrical stability of spin-coated 5,11-bis(triethylsilylethynyl)anthradithiophene (TES-ADT) thin-film transistors (TFTs) in which crosslinked poly(4-vinylphenol-co-methyl methacrylate) (PVP-co-PMMA) was utilized as a gate insulator layer. Atomic force microscopy observations show molecular terraces with domain boundaries in the spin-coated TEST-ADT semiconductor film. The TFT performance was observed to be superior in the ambient air condition.

Comparative Study of Triboelectric Nanogenerators with Differently Woven Cotton Textiles for Wearable Electronics.

A comparative study of the electrical performance of triboelectric nanogenerators (TENGs) with plain- and 2/1 twill-woven cotton textiles was conducted. Furthermore, the microstructures of the cotton fiber surfaces were examined to understand the fundamental mechanical interaction among the cotton fibers in the TENGs. The TENG with 2/1 twill-woven cotton textiles exhibited higher output voltages compared to that with plain-woven cotton textiles.

Electrical Stability of Solution-Processed Indium Oxide Thin-Film Transistors.

We investigated the electrical stability of bottom-gate/top-contact-structured indium oxide (In₂O₃) thin-film transistors (TFTs) in atmospheric air and under vacuum. The solution-processed In₂O₃ film exhibits a nanocrystalline morphology with grain boundaries. The fabricated In₂O₃ TFTs operate in an -type enhancement mode.

Effect of UV and Water on Electrical Properties at Pre- and Post-Annealing Processes in Solution-Processed InGaZnO Transistors.

There are some reports related to applications of ultraviolet (UV) and water to enhance the electrical performance of metal oxide thin-film transistors (TFTs). We recently discovered that treatment timing and treatment method are also important for a good metal oxide thin-film formation. There are different influences on the metal oxide TFTs' electrical properties based on the UV irradiation and water treatment timing.

Nonlinear Transport in Organic Thin Film Transistors with Soluble Small Molecule Semiconductor.

Nonlinear transport is intensively explained through Poole-Frenkel (PF) transport mechanism in organic thin film transistors with solution-processed small molecules, which is, 6,13-bis(triisopropylsilylethynyl) (TIPS) pentacene. We outline a detailed electrical study that identifies the source to drain field dependent mobility. Devices with diverse channel lengths enable the extensive exhibition of field dependent mobility due to thermal activation of carriers among traps.

Stability Study of Flexible 6,13-Bis(triisopropylsilylethynyl)pentacene Thin-Film Transistors with a Cross-Linked Poly(4-vinylphenol)/Yttrium Oxide Nanocomposite Gate Insulator.

We investigated the electrical and mechanical stability of flexible 6,13-bis(triisopropylsilylehtynyl)pentacene (TIPS-pentacene) thin-film transistors (TFTs) that were fabricated on polyimide (PI) substrates using cross-linked poly(4-vinylphenol) (c-PVP) and c-PVP/yttrium oxide (Y₂O₃) nanocomposite films as gate insulators. Compared with the electrical characteristics of TIPS-pentacene TFTs with c-PVP insulators, the TFTs with c-PVP/Y₂O₃ nanocomposite insulators exhibited enhancements in the drain current and the threshold voltage due to an increase in the dielectric capacitance. In electrical stability experiments, a gradual decrease in the drain current and a negative shift in the threshold voltage occurred during prolonged bias stress tests, but these characteristic variations were comparable for both types of TFT.

Optical design for single-mode and single-cell gap transflective liquid crystal displays.

Generally, for transflective liquid crystal displays with different modes and different cell gaps between the refractive and transmissive parts, precise process control to pattern the electrode and match the cell gaps may reduce the yield and thus, require high cost. This paper proposes a simple transflective liquid crystal display with a single-mode and single-cell thickness without a patterned electrode to achieve better productivity. The proposed transflective liquid crystal display consists of three half-wave retardation films, two quarter-wave retardation films, and an LC layer, whose optical performance was confirmed by both simulation and experiment.

Thermally tunable-focus lenticular lens using liquid crystal.

A thermally tunable focusing lenticular liquid crystal (LC) lens array was fabricated using a polymer LC component, including a polarizer that produces linearly polarized light. The focal length in the proposed structure could be tuned by temperature-adjusted applied voltage to a transparent heater in a lenticular LC lens cell because it alters the birefringence of the LC and varies the difference in refractive index between the LC and the polymer. The results showed that the focal length of the E7 LC used varied continuously with temperature from 5.

Reducing temperature dependence of the output energy of a quasi-continuous wave diode-pumped Nd:YAG laser.

It is demonstrated by numerical modeling that spectrally dispersed compound pumping diodes and low-loss pumping chamber reduced the temperature dependence of the output energy of quasi-continuous wave diode-pumped Nd:YAG lasers considerably. Several compound diodes with different spectral profiles were tested for pumping. The laser energy was calculated as a function of diode temperature from -30°C to 60°C.

Analysis of a color-matching backlight system using a blazed grating and a lenticular lens array.

A high efficiency LCD employing a color-matching backlight system that consists of a collimation lenticular lens sheet, a blazed grating, and a focusing lenticular lens array is proposed and analyzed. The RGB lights that are collimated and dispersed from the collimation lenticular lens sheet and the blazed grating are incident on the RGB color filters by the focusing lenticular lens array. The color-matched transmittance was increased 183% and 121% for divergence angles of 2° and 11°, respectively, compared to a conventional backlight that does not use a blazed grating.

Reflective color display using thermochromic pigments.

A reflective thermochromic display fabricated by a very simple method using three kinds of thermochromic pigments is produced and its thermo-optical characteristics are investigated. The display exhibits maximum red, green, and blue reflectances of 38%, 30%, and 35%, respectively. The reflective display cell shows continuous gray color with changing temperature, which is crucial for multicolor displays.

Zenithal alignment of liquid crystal on homeotropic polyimide film irradiated by ion beam.

We investigate the pretilt characteristics of a nematic liquid crystal [LC] in terms of ion beam exposure conditions on the homeotropic polyimide alignment layer. The pretilt angle of LCs in the case of high-energy ion beam treatment was decreased considerably almost the same to that of the homogenous alignment layer though we used homeotropic polyimide film at first. Increasing irradiating energy, we could control the pretilt from 90° to 1° with several steps.

Single-cell gap-transflective liquid crystal display using two optical modes of a bistable liquid crystal.

We present a single-cell gap-transflective liquid crystal display (LCD) characterized by a π cell having bulk-type liquid crystal (LC) bistability and an optical film configuration. The π cell has two stable states, which are a twisted and a nontwisted LC state. We used the twisted LC state for the reflective part connected with nonpatterned electrodes, producing a vertical field in the proposed transflective LCD.

Determination of actual surface azimuthal anchoring strength using a wedge-shaped liquid crystal cell.

We present a method that determines the actual surface azimuthal anchoring strength based on the torque balance. It is found by an optical technique of measuring simultaneously the cell thicknesses and twist angles at two regions of a wedge-type liquid crystal cell whose cell thickness varies continuously between different positions in the cell.

Measurement of displacement and vibration by using the oblique ray method.

An optical system that can measure vibrations and displacements is developed by using the oblique ray method. By employing a single convex lens that plays both roles of sending and receiving the beams that are reflected by the target surface, the optical measurement system became compact and reliable. A position-sensitive detector is used to measure the position change of the beam spot on the target surface.