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.

Physics of Liquid Crystals

Foreword. Series Editor's Foreword. Preface. 1. Liquid crystal physics.* Introduction.* Thermodynamics and statistic physics.* Orientational order.* Elastic properties of liquid crystals.* Response of liquid crystals to electro-magnetic fields.* Anchoring effects of nematic liquid crystal at surfaces. 2. Propagation of light in anisotropic optical medium.* Electromagnetic wave.* Polarization.* Propagation of light in uniform anisotropic optical media.* Propagation of light in cholesteric liquid crystals. 3. Optical modeling methods.* Jones matrix method.* Mueller matrix method.* Berreman 4x4 method. 4. Effects of Electric field on Liquid Crystals.* Dielectric interaction.* Flexoelectric Effect.* Ferroelectricity in liquid crystals. 5. Freedericksz transition.* Calculus of variation.* The Fredeericksz transition: statics.* The Freedericksz transition: dynamics. 6. Liquid Crystal Materials.* Introduction.* Refractive indices.* Dielectric constants.* Rotational Viscosity.* Elastic constant.* Figure-of-merits.* Refractive index matching between liquid crystals and polymers. 7. Modeling of liquid crystal director configuration.* Electric energy of liquid crystals.* Modeling electric field.* Simulation of liquid crystal director configuration. 8. Transmissive liquid crystal display.* Introduction.* Twisted nematic cells.* In plane switching (IPS) mode.* Vertical alignment (VA) mode.* Multi-domain Vertical Alignment (MVA) Cells.* Optically compensated bend (OCB) cell. 9. Reflective and Trasreflective display.* Introduction.* Reflective liquid crystal displays.* Transflector.* Classification of Transflective LCDs.* Dual-cell-gap Transflective LCDs.* Single-cell-gap Transflective LCDs.* Performance of transflective LCDs. 10. Liquid crystal display matrices, drive schemes and bistable displays.* Segmented displays.* Passive matrix displays and drive scheme.* Active Matrix Displays.* Bistable ferroelectric liquid crystal displays and drive scheme.* Bistable nematic displays.* Bistable cholesteric reflective display. 11. Liquid crystal/polymer composites. * Introduction.* Phase separation.* Scattering properties of liquid crystal/polymer composites.* Polymer dispersed liquid crystals.* Polymer stabilization liquid crystals.* Displays from liquid crystal/polymer composites. 12. Tunable liquid crystal photonic devices. * Introduction.* Laser beam steering.* Variable Optical Attenuators.* Tunable-Focus Lens.* Polarization-Independent LC Devices. Index.

Fundamentals of Liquid Crystal Devices

Recently, 'Liquid crystal display (LCD) vs. organic light-emitting diode (OLED) display: who wins?' has become a topic of heated debate. In this review, we perform a systematic and comparative study of these two flat panel display technologies. First, we review recent advances in LCDs and OLEDs, including material development, device configuration and system integration. Next we analyze and compare their performances by six key display metrics: response time, contrast ratio, color gamut, lifetime, power efficiency, and panel flexibility. In this section, we focus on two key parameters: motion picture response time (MPRT) and ambient contrast ratio (ACR), which dramatically affect image quality in practical application scenarios. MPRT determines the image blur of a moving picture, and ACR governs the perceived image contrast under ambient lighting conditions. It is intriguing that LCD can achieve comparable or even slightly better MPRT and ACR than OLED, although its response time and contrast ratio are generally perceived to be much inferior to those of OLED. Finally, three future trends are highlighted, including high dynamic range, virtual reality/augmented reality and smart displays with versatile functions.

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Liquid crystal display and organic light-emitting diode display: present status and future perspectives

Presently, liquid crystal displays (LCDs) and organic light-emitting diode (OLED) displays are two dominant flat panel display technologies Recently, inorganic mini-LEDs (mLEDs) and micro-LEDs (μLEDs) have emerged by significantly enhancing the dynamic range of LCDs or as sunlight readable emissive displays "mLED, OLED, or μLED: who wins?" is a heated debatable question In this review, we conduct a comprehensive analysis on the material properties, device structures, and performance of mLED/μLED/OLED emissive displays and mLED backlit LCDs We evaluate the power consumption and ambient contrast ratio of each display in depth and systematically compare the motion picture response time, dynamic range, and adaptability to flexible/transparent displays The pros and cons of mLED, OLED, and μLED displays are analysed, and their future perspectives are discussed

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Mini-LED, Micro-LED and OLED displays: present status and future perspectives

Metal silicides have played an indispensable role in the rapid developments of microelectronics since PtSi was first used to improve the rectifying characteristics of diodes in early 1960s. This wo ...

Metal silicides in CMOS technology : Past, present, and future trends

We have fabricated a nematic liquid crystal cell associated with a homogeneously aligned to twisted transition of a liquid crystal director. In the absence of an electric field, the liquid crystal molecule is homogeneously aligned under the crossed polarizers, and thus the cell appears to be black. When a fringe field induced by interdigital electrodes is applied, liquid crystal molecules rotate in plane even above electrodes and thus the cell transmits light. The device exhibits a high transmittance ratio as well as a wide viewing angle, which solves a long standing problem of low transmittance existing in the conventional in-plane switching mode. We show that the distance between electrodes smaller than the width of an electrode and cell gap is required for generating fringe field with applied voltage and rotating molecules above electrodes. We also investigate the mechanism of fringe-field switching and dependence of electro-optic effect on different cell conditions and dielectric anisotropy of liquid ...

Electro-optic characteristics and switching principle of a nematic liquid crystal cell controlled by fringe-field switching

http://esl.ecsdl.org/content/2/2/88.full.pdf

A Gate Electrode Fabrication Technique Using Dichlorosilane‐Based W ‐ Polycide with Monosilane‐Based WSi x Nucleation Layer

Remarkable reduction of contact resistance in the metal-p+ silicon Schottky barriers is obtained using the BF2/B mixed implant instead of the BF2 implant. Upon the annealing, higher remaining contents of both boron and fluorine in a shallow p+ surface layer are observed in the mixed implanted silicon. Variation of the dopants loss observed with different F doses is explained by introducing the following two types of surface reaction, i.e., (1) recombination of F–Si to make gaseous fluorosilyl/oxyfluorosilyl products and (2) recombination of F–B to form gaseous boron fluorides. Increasing the amount of the F–B reaction accelerates the recombination reaction of F–Si due to the reduced surface p+ doping level, and then results in the anomalous enhancement of the F removal. For the mixed implant, shortening of the average interdopant separation due to higher B contents within the contact depletion width reduces the potential fluctuations induced by the dopant discreteness, and thus leads to the improved unifo...

Analysis of the improved contact resistance in metal-p+ silicon Schottky barriers using the BF2/B mixed implantation

We investigated the dependence of channeling suppression on wafer tilt angles for sub-5 keV B/sup +/ and sub-15 keV BF/sub 2/ implantations using a ultra-low energy ion implanter. A noticeable reduction of channeling tail for 1 keV B/sup +/ and 4.5 keV BF/sub 2/ implants was demonstrated to require tilt angles greater than 8/spl deg/. These results are compared with recently published Monte-Carlo simulation data which indicate that ion redistribution at tail region is dominated by channeling along direction with estimated critical angle of 9/spl deg/ for 1 keV B/sup +/. For boron energy at 3.3 keV, wafer tilt of 8/spl deg/ remarkably suppressed the channeling. We also observed that 15 keV BF/sub 2/ implantation, as an equivalent energy of 3.3 keV B/sup +/, with tilt angle of 4/spl deg/ was sufficient for suppressing the channeling tail in dopant distribution due to additional suppression effect of channeling by implant-induced surface amorphization.

Critical angle of channeling for low energy ion implantation

We developed an additional nitrogen ion implantation process to suppress the abnormal oxidation of polycrystalline WSi/sub x//P-doped Si stack gate electrode during gate re-oxidation around 750/spl deg/C. The abnormal oxidation was attributed to oxidation during gate re-oxidation, resulting in deformation of the gate electrode profile. A method to suppress the abnormal oxidation is to employ pre-annealing in nitrogen ambient over 850/spl deg/C before gate re-oxidation; however, it leads to unstable pMOSFETs due to high thermal budget. Thus, we introduced the nitrogen implantation (N/sup +/ 10 keV/5/spl times/10/sup 15/ cm/sup -2/) prior to gate re-oxidation to improve the oxidation resistance of WSi/sub x/. The abnormal oxidation of WSi/sub x/ was effectively suppressed by nitrogen ion implantation. Moreover, the additional nitrogen ion implantation did not degrade gate oxide integrity (GOI).

Sahng-Kyoo Lee

Papers

Electro-optic characteristics and switching principle of a nematic liquid crystal cell controlled by fringe-field switching

A Gate Electrode Fabrication Technique Using Dichlorosilane‐Based W ‐ Polycide with Monosilane‐Based WSi x Nucleation Layer

Analysis of the improved contact resistance in metal-p+ silicon Schottky barriers using the BF2/B mixed implantation

Critical angle of channeling for low energy ion implantation

Suppression of abnormal oxidation of WSi/sub x//P-doped Si stack gate electrode during gate re-oxidation by additional nitrogen ion implantation