Yoshiaki Hisakado

Bio: Yoshiaki Hisakado is an academic researcher from Kyushu University. The author has contributed to research in topics: Birefringence & Liquid crystal. The author has an hindex of 3, co-authored 4 publications receiving 2152 citations.

Polymer-stabilized liquid crystal blue phases

Abstract: Blue phases are types of liquid crystal phases that appear in a temperature range between a chiral nematic phase and an isotropic liquid phase. Because blue phases have a three-dimensional cubic structure with lattice periods of several hundred nanometres, they exhibit selective Bragg reflections in the range of visible light corresponding to the cubic lattice. From the viewpoint of applications, although blue phases are of interest for fast light modulators or tunable photonic crystals, the very narrow temperature range, usually less than a few kelvin, within which blue phases exist has always been a problem. Here we show the stabilization of blue phases over a temperature range of more than 60 K including room temperature (260–326 K). Furthermore, we demonstrate an electro-optical switching with a response time of the order of 10−4 s for the stabilized blue phases at room temperature.

Fast electro-optical effect in polymer-stabilized blue phases

Abstract: Key challenges in achieving higher-quality liquid crystal displays for future generations are developing new liquid crystal materials with faster electro-optical response and simplifying the fabrication process of devices. Blue phases1-4, kinds of liquid crystal phases, have two major advantages over commonly used nematic phases. First, the response is much faster5-8. Second, the zero-electric field state is optically isotropic unlike nematic phases, that is, no surface treatment (no rubbing) is necessary, leading to a simplification of the fabrication process. One of the problems of blue phases that the available temperature range is very narrow has been overcome by our recent achievement, the polymer-stabilized blue phases9,10. Here we show that the polymer-stabilized blue phases surmount another problem that the blue phase is very fragile to an electric field. We also demonstrate the sufficiently large electric field-induced birefringence and the micro-second response of the polymer-stabilized blue phases without any surface treatment.© (2004) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Physics of Liquid Crystals

Abstract: Over the 100 years since its discovery, liquid crystals have been the intriguing subject for both academia and industries. The textbook of de Gennes The Physics of Liquid Crystals published in 1974 is still the bible for many LC researchers, but new subjects unmentioned in the book have also risen for these years. This chapter describes the story of the recent developments and the future perspectives in physics of liquid crystals, especially focusing on the contributions by Japanese research groups for the last decade.

Semiconductor device, and manufacturing method thereof

Abstract: An object is to provide a semiconductor device of which a manufacturing process is not complicated and by which cost can be suppressed, by forming a thin film transistor using an oxide semiconductor film typified by zinc oxide, and a manufacturing method thereof. For the semiconductor device, a gate electrode is formed over a substrate; a gate insulating film is formed covering the gate electrode; an oxide semiconductor film is formed over the gate insulating film; and a first conductive film and a second conductive film are formed over the oxide semiconductor film. The oxide semiconductor film has at least a crystallized region in a channel region.

Semiconductor device and display device

Abstract: An object of the present invention is to decrease the resistance of a power supply line, to suppress a voltage drop in the power supply line, and to prevent defective display. A connection terminal portion includes a plurality of connection terminals. The plurality of connection terminals is provided with a plurality of connection pads which is part of the connection terminal. The plurality of connection pads includes a first connection pad and a second connection pad having a line width different from that of the first connection pad. Pitches between the plurality of connection pads are equal to each other.

Semiconductor device, electronic device, and method of manufacturing semiconductor device

Abstract: To provide a semiconductor device and a display device which can be manufactured through a simplified process and the manufacturing technique. Another object is to provide a technique by which a pattern of wirings or the like which is partially constitutes a semiconductor device or a display device can be formed with a desired shape with controllability.

62.2: Invited Paper: Fast Electro‐Optical Switching in Polymer‐Stabilized Liquid Crystalline Blue Phases for Display Application

Abstract: Blue phases have two major advantages over commonly used nematic phases:1) the response is much faster, 2) the zero-electric field state is optically isotropic. We demonstrate the sufficiently large electric field-induced birefringence and the micro-second response of the polymer-stabilized blue phases and the induced-isotropic phases without any surface treatment.