Single Cell Gap Transflective Liquid Crystal Display with Slanted Reflector Above Transmissive Pixels

Single cell gap transflective liquid crystal display which provides that the backlight traverses the reflective pixel portion twice and thereby follows a path similar to that of the ambient light. A slant reflector is built on the path of the back light to reflect the transmitted light to the reflective portion so that the back light and ambient light follow similar paths

Enhancement of polar phases in PVDF by forming PVDF/SiC nanowire composite

Different contents of silicon carbide (SiC) nanowires were mixed with Poly(vinylidene fluoride) (PVDF) to facilitate the polar phase crystallization. It was shown that the annealing temperature and SiC content affected on the phase and crystalline structures of PVDF/SiC samples. Furthermore, the addition of SiC nanowire enhanced the transformation of non-polar α phase to polar phases and increased the relative fraction of β phase in PVDF. Due to the nucleating agent mechanism of SiC nanowires, the ion-dipole interaction between the negatively charged surface of SiC nanowires and the positive CH2 groups in PVDF facilitated the formation of polar phases in PVDF

70.3: Current‐Scaling a‐Si:H TFT Pixel Electrode Circuit for AM‐OLEDs

We fabricated and characterized the amorphous silicon thin‐film transistor (a‐Si:H TFT) pixel electrode circuit with currentscaling function that can be used for active‐matrix organic lightemitting displays (AM‐OLEDs). As expected from previously reported simulation results, fabricated circuit showed an acceptable current‐scaling performance for a high‐resolution AM‐OLED based on a‐Si:H TFTs.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/92085/1/1.2451422.pd

P‐143: A Novel Current‐Scaling a‐Si:H TFTs Pixel Electrode Circuit for Active‐Matrix Organic Light‐Emitting Displays

Hydrogenated amorphous silicon thin‐film transistor (a‐Si:H TFT) pixel electrode circuit with a function of current scaling is proposed for active‐matrix organic light‐emitting displays (AM‐OLEDs). In contrast to the conventional current mirror pixel electrode circuit, in this circuit a high data‐to‐organic light‐emitting device (OLED) current ratio can be achieved, without increasing the a‐Si:H TFT size, by using a cascade structure of storage capacitors. Moreover, the proposed circuit can compensate for the variations of TFT threshold voltage. Simulation results, based on a‐Si:H TFT and OLED experimental data, showed that a data‐to‐OLED current ratio larger than 10 and a fast pixel programming time can be accomplished with the proposed circuit.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/92010/1/1.2036579.pd

P‐13: Photosensitivity of Amorphous IGZO TFTs for Active‐Matrix Flat‐Panel Displays

We studied the optical and electrical properties of the amorphous indium gallium zinc oxide thin‐film transistors (a‐IGZO TFTs). To develop a‐IGZO density‐of‐states model, intrinsic a‐IGZO optical properties such as optical band gap and Urbach energy, and TFT characteristics under illumination are investigated. During the a‐IGZO TFTs illumination with the wavelengths ranging from 460 to 660 nm, the off‐state drain current only slightly increases while a large increase was observed for the wavelength below 400 nm. Threshold voltage and subthreshold swing are also only slightly modified between 460 to 660 nm, while field‐effect mobility is almost unchanged in the investigated photon energy range. The observed results are consistent with the a‐IGZO optical energy band gap of about 3.05 eV. This study suggest that the a‐IGZO TFTs are light sensitive above 3.0 eV and photogenerated electrons are more mobile than holes within device channel region.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/92030/1/1.3069354.pd

Magnetic Behavior of a Mixed Ising Ferrimagnetic Model in an Oscillating Magnetic Field

The magnetic behavior of a mixed Ising ferrimagnetic system on a square lattice, in which the two interpenetrating square sublattices have spins +- 1/2 and spins +-1,0, in the presence of an oscillating magnetic field has been studied with Monte Carlo techniques. The model includes nearest and next-nearest neighbor interactions, a crystal field and the oscillating external field. By studying the hysteretic response of this model to an oscillating field we found that it qualitatively reproduces the increasing of the coercive field at the compensation temperature observed in real ferrimagnets, a crucial feature for magneto-optical applications. This behavior is basically independent of the frequency of the field and the size of the system. The magnetic response of the system is related to a dynamical transition from a paramagnetic to a ferromagnetic phase and to the different temperature dependence of the relaxation times of both sublattices.Comment: 10 figures. To be published in Phys.Rev

Polymer sieving matrices in microanalytical electrophoresis

Microfluidic design has advanced existing protein separation capabilities and supported novel assays. Key metrics for successful protein separations include fast, robust, and sensitive analysis of complex mixtures of bio-macromolecules. Attaining high separation resolution is a chief concern. Here we review recent advances in polymer-based electrophoresis sieving materials that are impacting microfluidic bioanalytical applications. Looking forward, we comment on unmet needs for advanced separation media in micro-to-nanoscale devices

Micro Optical Components For Enhancing The Image Quality Of Transflective Lcds

The micro optical elements can resolve the key issues of transflective liquid crystal displays (LCDs), such as low optical efficiency, different response time, and inadequate color saturation of the transmissive pixels, and low brightness, narrow viewing angle, non-uniform reflected light distribution of the reflective pixels. The results demonstrated that a much higher image quality with excellent legibility under both bright and dark ambient conditions for transflective LCDs can be achieved by an image-enhanced reflector and a random grating reflector

Applications Of Multidirectional Asymmetrical Microlens-Array Light-Control Films On Reflective Liquid-Crystal Displays For Image Quality Enhancement

The multidirectional asymmetrical microlens-array light-control film (MAMA-LCF) is developed for enhancing the image brightness and contrast ratio of various reflective liquid-crystal displays. By use of index-matching material, the interface reflection is greatly reduced. Through optimized designs, the surface-scattering effect is also suppressed; thus the contrast ratio is much enhanced. From experimental results, the MAMA-LCF leads to a ∼1.5× gain in brightness over the MgO standard white and a 15:1 contrast ratio for the reflective color super-twist nematic liquid-crystal display, 2.8× MgO and a 23:1 contrast ratio for the polymer-dispersed liquid-crystal, and 2.8× MgO and a 13:1 contrast ratio for the cholesteric liquid-crystal display. Potential applications of this low-cost plastic thin film for reflective liquid-crystal displays are foreseeable. © 2004 Optical Society of America

Highly anisotropic metasurface : a polarized beam splitter and hologram

Two-dimensional metasurface structures have recently been proposed to reduce the challenges of fabrication of traditional plasmonic metamaterials. However, complex designs and sophisticated fabrication procedures are still required. Here, we present a unique one-dimensional (1-D) metasurface based on bilayered metallic nanowire gratings, which behaves as an ideal polarized beam splitter, producing strong negative reflection for transverse-magnetic (TM) light and efficient reflection for transverse-electric (TE) light. The large anisotropy resulting from this TE-metal-like/TM-dielectric-like feature can be explained by the dispersion curve based on the Bloch theory of periodic metal-insulator-metal waveguides. The results indicate that this photon manipulation mechanism is fundamentally different from those previously proposed for 2-D or 3-D metastructures. Based on this new material platform, a novel form of metasurface holography is proposed and demonstrated, in which an image can only be reconstructed by using a TM light beam. By reducing the metamaterial structures to 1-D, our metasurface beam splitter exhibits the qualities of cost-efficient fabrication, robust performance, and high tunability, in addition to its applicability over a wide range of working wavelengths and incident angles. This development paves a foundation for metasurface structure designs towards practical metamaterial applications