Yong Eui Lee

A Triple-Layered Microcavity Structure for Electrophoretic Image Display

An electrophoretic display (EPD) cell with a triple-layered microcavity structure was fabricated using a convenient dry film resist. The inherent structural advantage arising from the function of the middle channel layer as a background colored state enabled the EPD to operate with two different-colored states by using a single type of electronic-ink particles, thereby eliminating the possible agglomeration of oppositely charged ink particles and supporting the potential application of the proposed structure to color the electronic paper. The preliminary operation of this new EPD structure was demonstrated as white and blue display states on a rigid glass exhibiting a contrast ratio of 1.5 : 1 with saturation voltages of + 30 and -30 V, respectively. Successful demonstrations on both the indium-tin-oxide-patterned glass and flexible polyethylene substrates are also provided.

Microencapsulation of Polymer Coated Color Pigments for Multi-Color Electrophoretic Display

In this study, we have investigated microencapsulation of magenta, yellow, and cyan color polymer balls with white pigment for multi-color electrophoretic display implementation. The charged color pigments have been prepared by physical coating of magenta, yellow, and cyan with functionalized polymers, then surface charging with charge control agent. These color balls with white pigment were microencapsulated in suspending fluid through in-situ polymerization.

P‐107: Low Voltage Driving Color Active Matrix Electrophoretic Display

We have prepared ZnO TFT driving color AMEPD using nano-scale electrophoretic ink particles made by invented modified emulsion process. New concept of color filter using silver halide technology — similar with photographic technology-which is suitable for reflective EPD application was adapted to develop color filters. To get rid of align process for color filters and TFT arrays, transparent ZnO TFT with low temperature process was fabricated. In case of monochrome EPD, the contrast ratio was 23:1 at operating voltage of ± 10V. Zone color prototype AMEPD was fabricated with silver halide color filter.

Thin Film Morphology and GrowthMechanism of Pentacene Thin Film Using Low-Pressure Organic Vapor Deposition

We have investigated the growth mechanism and thin film morphology of pentacene thin films by the process of low-pressure gas assisted organic vapor deposition (LP-GAOVD). As the source temperature, flow rate of the carrier gas, substrate temperature and chamber pressure were varied, the growth rate, morphology and grain size of the films were differently obtained. The electrical properties of pentacene thin films for applications in organic thin film transistor and electrophoretic displays were discussed