• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
• /
• pp.431-433
• /
• 2009

We developed 4.8 inch WQVGA e-paper on plastic substrate using organic field effect transistors (OFETs). Polyethylene naphthalate (PEN) film was used as a flexible substrate and arrays of OFETs with bottom-gate, bottom-contact structure were fabricated on it. Lowtemperature curable organic gate insulating materials were employed and polymer semiconductor solutions were ink-jetted on arrays with high-resolution. At all steps, process temperature was limited below $130^{\circ}C$. Finally, we could drive flexible e-paper displays based on OFET arrays with the resolution of 100 dpi.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
• /
• pp.822-825
• /
• 2006

We propose a transflective In-Plane Switching mode in which patterned retarder is placed only on the reflective area of the upper substrate side. By selecting optic axes of Half Wavelength Plate and Liquid Crystal as 24 and 90 degree with respect to polarizer, condition of low reflectance for visible wavelength range at black state is found.

• 반도체디스플레이기술학회지
• /
• 제21권2호
• /
• pp.7-10
• /
• 2022

A functional polyethylene terephthalate substrate to increase light extraction efficiency of organic light-emitting diodes is studied. We formed nano-structured PET surfaces by controlling the power, gas, and exposure time of the linear ion-beam. The haze of the polyethylene terephthalate can be controlled from 0.2% to 76.0% by changing the peak-to-valley roughness of nano structure by adjusting the exposure cycle. The treated polyethylene terephthalate shows average haze of 76.0%, average total transmittance of 86.6%. The functional PET increases the current efficiency of organic light-emitting diodes by 47% compared to that of organic light-emitting diode on bare polyethylene terephthalate. In addition to polyethylene terephthalate with light extraction performance, by conducting additional research on the development of functional PET with anti-reflection and barrier performance, it will be possible to develop flexible substrates suitable for organic light-emitting diodes lighting and transparent flexible displays.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
• /
• pp.863-866
• /
• 2008

For the cost reduction in the fabrication of display panels, a reverse moving system was equipped to a compacted in-line wet etch/cleaning system. For the effect of the alternating movement of substrate on the wet etch process, ITO layers were etched in various moving modes of substrates and the results were compared and analyzed.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권1호
• /
• pp.159-161
• /
• 2007

We fabricated flexible OTFT-backplanes for the electrophoretic display(EPD). The OTFTs employed bottom contact structure on PEN substrate and used the cross-linked polyvinylphenol for gate insulator, pentacene for active layer. Especially, we used PVA/Acryl double layers for passivation of backplane as well as for pixel dielectric layer between backplane and EPD panel. The OTFT-EPD panel worked successfully anddemonstrated to display some patterns.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2010년도 제39회 하계학술대회 초록집
• /
• pp.167-167
• /
• 2010

Indium tin oxide (ITO) has been widely used as transparent conductive oxides (TCOs) for transparent electrodes of various optoelectronic devices, such as liquid crystal displays (LCD) and organic light emitting diodes (OLED). However, indium has become increasingly expensive and rare because of its limited resources. In addition, ITO thin films have some problems for OLED and flexible displays, such as imperfect work function, chemical instability, and high deposition temperature. Therefore, multi-component TCO materials have been reported as anode materials. Among the various materials, IZTO thin films have been gained much attention as anode materials due to their high work function, good conductivity, high transparency and low deposition temperature. IZTO thin films with a thickness of 200nm were deposited on Corning glass substrate at different substrate temperature by pulsed DC magnetron sputtering with a sintered ceramic target of IZTO (In2O3 70 wt%, ZnO 15 wt%, SnO2 15 wt%). We investigated the electrical, optical, structural properties of IZTO thin films. As the substrate temperature is increased, the electrical properties of IZTO are improved. All IZTO thin films have good optical properties, which showed an average of transmittance over 80%. These IZTO thin films were used to fabricate organic light emitting diodes (OLEDs) as anode and the device performances studied. As a result, IZTO has utility value of TCO electrode although it reduced indium and we expect it is possible for the IZTO to apply to flexible display due to the low processing temperature.

• 반도체디스플레이기술학회지
• /
• 제22권4호
• /
• pp.142-147
• /
• 2023

This paper presents a novel design of a differential patch antenna for 60-GHz millimeter-wave applications. The design process of the back-to-back (BTB) patch antenna is based on the conventional single-patch antenna. The initial design of the BTB patch antenna (Type-I) has a patch size of 0.66 × 0.98 mm² and a substrate size of 0.99 × 1.48 mm². It has a gain of 1.83 dBi and an efficiency of 94.4% with an omni-directional radiation pattern. A 0.4 mm-thick high-resistivity silicon (HRS) is employed for the substrate of the BTB patch antenna. The proposed antenna is further analyzed to investigate the effect of substrate size and resistivity. As the substrate resistivity decreases, the gain and efficiency degrade due to the substrate loss. As the substrate (HRS) size decreases approaching the patch size, the resonant frequency increases with a higher gain and efficiency. The BTB patch antenna has optimal performances when the substrate size matches the patch size on the HRS substrate (Type-II). The antenna is redesigned to have a patch size of 0.81 × 1.18 mm² on the HRS substrate in the same size. It has an efficiency of 94.9% and a gain of 1.97 dBi at the resonant frequency of 60 GHz with an omni-directional radiation pattern. Compared to the initial design of the BTB patch antenna (Type-I), the optimal BTB patch antenna (Type-II) has a slightly higher efficiency and gain with a considerable reduction in antenna area by 34.8%.

• Journal of the Optical Society of Korea
• /
• 제17권2호
• /
• pp.168-171
• /
• 2013

A reflective flexible display was fabricated by placing a thermochromic pigment on a polyethylene naphthalate (PEN) substrate coated with an indium tin oxide (ITO) film, and its thermo-optical characteristics were investigated. The reflective thermochromic display showed good image quality with a reflectance of approximately 65%. As a flexible display, the display showed reliability without damage to the image even after the display was bent strongly. The reflective display cell exhibits continuously the gray level according to the temperature controlled by applied voltage. This low cost display is expected be used in outdoor poster applications where information needs to be presented clearly.

• Journal of Information Display
• /
• 제6권3호
• /
• pp.30-35
• /
• 2005

We have developed a paper-like display using polymer particles charged triboelectrically. By using a toner-type display with a simple structure, we continued that polymer particle movement is controlled by only a voltage difference between scan and data electrode. We fabricated a diagonal 2.4 inch panel on the glass substrate and successfully produced an image by the passive driving method with operating voltages of about ${\pm}$ 120 V. The contrast ratio was 4:1.

• 반도체디스플레이기술학회지
• /
• 제11권1호
• /
• pp.29-33
• /
• 2012

In this study, we have investigated the structural and electrical characteristics of IZO thin films deposited under hydrogen atmosphere on flexible substrate for the OLED (organic light emitting diodes) devices. For this purpose, PES was used for flexible substrate and IZO thin films were deposited by RF magnetron sputtering under hydrogen ambient gases (Ar, $Ar+H^2$) at room temperature. In order to investigate the influences of the hydrogen, the flow rate of hydrogen in argon mixing gas has been changed from 0.1sccm to 0.5sccm. All the samples show amorphous structure regardless of flow rate. The electrical resistivity of IZO films increased with increasing flow rate of $H^2$ under $Ar+H^2$. All the films showed the average transmittance over 85% in the visible range. The OLED device was fabricated with different IZO electrodes made by configuration of IZO/$\acute{a}$-NPD/DPVB/$Alq_3$/LiF/Al to elucidate the performance of IZO substrate. OLED devices with the amorphous-IZO (a-IZO) anode film show good current density-voltage-luminance characteristics. This suggests that flat surface roughness and low electrical resistivity of a-IZO anode film lead to more efficient anode material in OLED devices.