A reflective electronic medium with properties similar to printed paper has been a goal within the display industry for many years. Most current reflective technologies use techniques similar to emissive displays to achieve color capability. This article focuses on a design that mimics color printing methods to achieve a wide color gamut and uses a roll‐to‐roll processing method.
p -type conducting films of α-BuCu2S2 have been deposited onto glass and KBr substrates, yielding a conductivity of 17 S/cm and a Hall mobility of 3.5 cm2/V s. For a 430-nm-thick film, the optical transparency approaches 90% in the visible portion of the spectrum at 650 nm, and a transparency of 40% extends throughout the infrared to the long-wavelength cutoff of the KBr substrate at 23 μm.
We present an approach by which submicrometer-spaced electrical contacts can be fabricated on virtually any surface under ultrahigh-vacuum conditions. The metallic contacts are formed by subsequent deposition through a macroscopic mask and a nanostructured stencil mask. The stencil mask with a high aspect ratio was obtained by nanopatterning of suspended low-stress Si3+xN4−x membranes with a focused ion-beam system. The fabricated contacts can be electrically connected in situ by simply exchanging the mask carrier by a second, spring-loaded, carrier.
Highly transparent ZnO-based thin-film transistors (TFTs) are fabricated with optical transmission (including substrate) of ∼75% in the visible portion of the electromagnetic spectrum. Current–voltage measurements indicate n-channel, enhancement-mode TFT operation with excellent drain current saturation and a drain current on-to-off ratio of ∼107. Threshold voltages and channel mobilities of devices fabricated to date range from ∼10 to 20 V and ∼0.3 to 2.5 cm2/V s, respectively. Exposure to ambient light has little to no observable effect on the drain current. In contrast, exposure to intense ultraviolet radiation results in persistent photoconductivity, associated with the creation of electron-hole pairs by ultraviolet photons with energies greater than the ZnO band gap. Light sensitivity is reduced by decreasing the ZnO channel layer thickness. One attractive application for transparent TFTs involves their use as select-transistors in each pixel of an active-matrix liquid-crystal display.
Kinase-mediated phosphorylation of proteins is critical to the regulation of many biological processes, including cell growth, apoptosis, and differentiation. Because of the central role that kinases play in processes that can lead to disease states, the targeting of kinases with small-molecule inhibitors is a validated strategy for therapeutic intervention. Classic methods for assaying kinases include nonhomogenous enzyme-linked immunosorbent assays or scintillation-based formats using [γ-32P]ATP. However, homogenous fluorescence-based assays have gained in popularity in recent years due to decreased costs in reagent usage through miniaturization, increased throughput, and avoidance of regulatory costs associated with the use of radiation. Whereas the readout signal from a nonhomogenous or radioactive assay is largely impervious to interferences from matrix components (such as library compounds), all homogenous fluorescent assay formats are subject to such interferences. Interference from intrinsically fluorescent compounds or from scattered light due to precipitated compounds can interfere with assays that depend on a fluorescence intensity (or fluorescence quenching), fluorescence resonance energy transfer, or fluorescence polarization-based readout. Because these interfering factors show a greater effect at lower wavelengths, one strategy to overcome such interferences is to develop fluorescent assays using longer wavelength (red-shifted) fluorescent probes. In this article, we describe the PanVera PolarScreen™ far-red fluorescence polarization assay format, which mitigates assay interference from autofluorescent compounds or scattered light through the use of a far-red tracer. The tracer shows substantially less interference from light scatter or autofluorescent library compounds than do fluorescein-based tracers, and gives rise to a larger assay window than the popular far-red fluorophore Cy5™.
Abstract Results of an investigation of bias stress metastability of multicomponent, zinc–indium and zinc–tin oxides, transistors are investigated. The bias stress as a function of various dielectrics, passivation layers, and illumination conditions indicate that for negative gate bias stressing defects often are created in the semiconductor, probably near or at the surface, particularly if the devices are unpassivated. Oxygen vacancy formation is a likely candidate. For many dielectrics, the positive gate bias metastability appears to be dominated by charge trapping within the insulator. For zinc–tin oxide devices, the kinetics of the metastability follows a stretched exponential behavior with a power law dependence on gate voltage. Correcting for the observed Meyer–Neldel behavior, the activation energy of τ is about 1.2 eV for defect generation and the disorder energy from β is about 0.06 eV. By using passivation, the best gate dielectrics and annealing protocols, we have reduced the bias stress metastability to about 0.1 V for a 25,000 s stress at 22 °C.
Abstract A novel architecture and proprietary electrically addressable inks have been developed to provide disruptive, print‐like full color reflective digital media solutions based on an electrokinetic technology platform. The thin, flexible, low‐power, reflective electronic media is fabricated with a new roll‐to‐roll manufacturing platform. Here we demonstrate the integration of this media with multi‐component oxide (MCO) thin‐film transistor (TFT) backplane for an active matrix reflective electronic display.
Amorphous silicon has long been the king of flat panel displays. It began its reign in PC monitors and high-definition TV, then conquered netbooks, e-readers, and smartphones. No other substance was as suitable for the thin-film transistors that sit behind a display's hundreds of thousands of pixels, turning each one on or off. But soon the dominion of amorphous silicon will pass, because it can't provide what coming generations of electronic products will require. For one thing, it isn't fast enough. Next-generation LCD TVs will be refreshed at least 240 times a second, which is two to four times as quick as today's versions; that way, they'll provide sharper fast-action sports and movies. Three-dimensional displays will need refresh rates twice again as high, to provide all that fast-motion goodness to each eye.
High mobility, n-type transparent thin-film transistors (TTFTs) with a zinc indium oxide (ZIO) channel layer are reported. Such devices are highly transparent with ∼85% optical transmission in the visible portion of the electromagnetic spectrum. ZIO TTFTs annealed at 600 °C operate in depletion-mode with threshold voltages −20 to −10V and turn-on voltages ∼3V less than the threshold voltage. These devices have excellent drain current saturation, peak incremental channel mobilities of 45–55cm2V−1s−1, drain current on-to-off ratios of ∼106, and inverse subthreshold slopes of ∼0.8V∕decade. In contrast, ZIO TTFTs annealed at 300 °C typically operate in enhancement-mode with threshold voltages of 0–10V and turn-on voltages 1–2V less than the threshold voltage. These 300 °C devices exhibit excellent drain–current saturation, peak incremental channel mobilities of 10–30cm2V−1s−1, drain current on-to-off ratios of ∼106, and inverse subthreshold slopes of ∼0.3V∕decade. ZIO TTFTs with the channel layer deposited near room temperature are also demonstrated. X-ray diffraction analysis indicates the channel layers of ZIO TTFTs to be amorphous for annealing temperatures up to 500 °C and polycrystalline at 600 °C. Low temperature processed ZIO is an example of a class of high performance TTFT channel materials involving amorphous oxides composed of heavy-metal cations with (n−1)d10ns0(n⩾4) electronic configurations.
