• Proceedings of the Materials Research Society of Korea Conference
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• 2009.05a
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• pp.13.1-13.1
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• 2009

Transparent electronics has attracted many interests, for it can open new applications for consumer electronics, transportation, business, and military. Among them, display backplane, thin film transistor (TFT) array would be the most attractive application. Many researchers have been investigating oxide semiconductors for transparent channel material of TFT since the report for transparent amorphous oxide semiconductor (TAOS) TFT by Hosono group and ZnO TFT by Wager group. Especially, oxide TFTs have been intensively investigated during a couple of years since the first demonstration of ZnO-TFT driving AM-OLED. Many papers regarding the fabrication and performance of oxide TFTs, and active matrix display driven by oxide TFTs have been reported. Now lots of people have confidence in the competitiveness of oxide TFTs for the backplane of AM-Display. Especially, high mobility, uniformity, fairly good stability, and low cost process make oxide TFTs applied even to a large size AM-OLED. Last year, Samsung mobile display, former SID, reported 12" AM-OLED driven by IZGO-TFT and it seems that the remained issue for the mass production is the bias temperature stability. Here, we will introduce the application of oxide TFT and important issue for oxide TFT to be used for the direct printing.

• Journal of the Semiconductor & Display Technology
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• v.21 no.1
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• pp.79-84
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• 2022

As various flexible display products are released, the demand for high-performance colorless and transparent polyimide (CPI) film is continuously increasing. The primary purpose of this study is to establish a systematic procedure for optimizing the optical performance of CPI films by applying the response surface method. After selecting three key factors (monomer type, stirring time for varnish synthesis, and maximum temperature of vacuum furnace for film production) affecting optical performance based on experiences and references, CPI films were manufactured according to the experimental sequence designed by the central composite design, and then the yellowness index (YI) and optical transmittance (Tr) of the films were measured. When producing a CPI film by pouring varnish into a petri dish, the change in optical properties according to thickness should be considered, and there was a meaningful linear relationship between YI and Tr. The species of monomer and the maximum temperature were the critical factors that had an influence on YI and Tr, respectively. It is expected that the procedure proposed in this study can serve as a starting point for CPI film optimization studies considering the other factors that were not considered and responses such as thermal properties.

• Journal of the Korean Ceramic Society
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• v.39 no.3
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• pp.226-232
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• 2002

We searched thermal stability of ${\alpha}-Fe_2O_3$ using red color filter for display. In the PDP(Plasma Display Panel), the color filter layer is lied normally between front glass and transparent dielectric materials, so it might be needed to study the reaction of ${\alpha}-Fe_2O_3$ and transparent dielectric materials. The transparent dielectric materials containing ZnO has good transparency. Red colorlayer of ${\alpha}-Fe_2O_3$ contacted with dielectric material layer containing ZnO is changed to colorlessness over 500$^{\circ}$C because ZnO defuse ${\alpha}-Fe_2O_3$, the dielectric materials without ZnO, however, maintain red color at the same condition. We suggest that a layer contacting with ${\alpha}-Fe_2O_3$ red color layer has to lie with transparent dielectric materials without ZnO, then the materials containing ZnO is coated over to get color of ${\alpha}-Fe_2O_3$ for red color filter

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1995.11a
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• pp.302-305
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• 1995

ITO(indium tin oxide) that is both conductive in electricity and transparent to the visible ray is called transparent conducting thin film. Nowaday, according to the development of flat panel display such as LCD(Liquid Crystal display, EL(electolumine- scence display), PDP(plasma display panel), ECD(electrocromic display), the higher quality in the low temperature process has been asked to reduce the production cost and to have a good uniformity on a large substrate. In this study, we prepared indium tin oxide(ITO) by a cylindrical DC magnetron sputtering with Indium-tin (9:1) alloy target instead of indium-tin oxide target. To reduce the defact in ITO, the effect on ITO by varing the magnetic field intensity and the applied voltage ares studied. the resistivity of the film deposited in oxygen partial pressure of 5% and substrate temperature of 140$^{\circ}C$. is 1.6${\times}$10$\^$-1/$\Omega$$.$cm with 85% optical transmission in viaible ray.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.1575-1577
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• 2009

We have investigated the characteristics of transparent indium zinc oxide(IZO)/Ag/IZO multilayer electrode grown on polyethylene terephthalate (PET) substrates using a specially designed roll-to-roll sputtering system for use in flexible device are described. By the continuous R2R sputtering of the bottom IZO, Ag, and top IZO layers at room temperature, we were able to fabricate an IZO-Ag-IZO multilayer electrode with a sheet resistance of 6.15 ${\Omega}$/square, optical transmittance of 87.4 %, and figure of merit value of 42.03 10-3 ${\Omega}$-1. In addition, the IZO-Ag-IZO multilayer electrode exhibited superior flexibility to the RTR sputter grown single ITO electrode, due to the existence a ductile Ag layer between the IZO layers. This indicates that the RTR sputtered IZO-Ag-IZO multilayer is a promising flexible electrode that can substitute for the conventional single ITO electrode grown by bath type sputtering for use in low cost flexible device, due to its low resistance, high transparency, superior flexibility and fast preparation by the R2R process.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.389.1-389.1
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• 2016

The flexible solid state device has been widely studied as portable and wearable device applications such as display, sensor and curved circuits. A zero-bias operation without any external power consumption is a highly-demanding feature of semiconductor devices, including optical communication, environment monitoring and digital imaging applications. Moreover, the flexibility of device would give the degree of freedom of transparent electronics. Functional and transparent abrupt p/n junction device has been realized by combining of p-type NiO and n-type ZnO metal oxide semiconductors. The use of a plastic polyethylene terephthalate (PET) film substrate spontaneously allows the flexible feature of the devices. The functional design of p-NiO/n-ZnO metal oxide device provides a high rectifying ratio of 189 to ensure the quality junction quality. This all transparent metal oxide device can be operated without external power supply. The flexible p-NiO/n-ZnO device exhibit substantial photodetection performances of quick response time of $68{\mu}s$. We may suggest an efficient design scheme of flexible and functional metal oxide-based transparent electronics.

• Journal of Satellite, Information and Communications
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• v.12 no.1
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• pp.54-57
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• 2017

In commercial facilities, it is very difficult in real to promote specific products among various products because various products are displayed and sold. Therefore, in order to promote information on most display products, there is a great tendency to rely on printed matter or salesperson. So, it is focused to display advertising or promotional video based on interactive user information by utilizing the diplay used in the store, and to implement technology considering energy saving. Also it is very utilized for a specific product sold or displayed at a commercial facility to be sent to manufacturer or advertiser who wants to promote specific products and content at customer contacts. In this study, we implemented that maximized advertisement effect through the advertisement video and combination of product using transparent display. we implemented User-oriented image display technology to provide an interactive service according to whether there is a user or not. Through this study, we proposed a new direction to maximize advertising/public relations effect in various commercial facilities.

• Journal of Broadcast Engineering
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• v.21 no.1
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• pp.43-50
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• 2016

In this paper, we present a distortion correction for wearable Augmented Reality (AR) on mobile phones. Head Mounted Display (HMD) using mobile phones, such as Samsung Gear VR or Google's cardboard, introduces lens distortion of the rendered image to user. Especially, in case of AR the distortion is more complicated due to the duplicated optical systems from mobile phone's camera and HMD's lens. Furthermore, such distortions generate mismatches of the visual cognition or perception of the user. In a natural way, we can assume that transparent wearable displays are the ultimate visual system which generates the least misperception. Therefore, the image from the mobile phone must be corrected to cancel this distortion to make transparent-like AR display with mobile phone based HMD. We developed a transparent-like display in the mobile wearable AR environment focusing on two issues: pincushion distortion and field-of view. We implemented our technique and evaluated their performance.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.167-167
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• 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.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.451-451
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• 2010

최근들어 80인치 이상의 대경 고화질 display 및 휴대용 projection display 제작이 가능한 LCoS (Liquid Crystal on Silicon) display에 대한 관심이 높아지고 있다. LCoS projection display는 높은 개구율, 빠른 응답속도, 고화질, 대형 디스플레이 임에도 불구하고 낮은 제조단가 등의 여러 가지 장점을 가지고 있다. LCoS projection display의 핵심 기술로는 높은 투과도와 낮은 반사율을 갖는 유리기판, 무기 배향막 증착 기술, Si back plane과의 접합기술 등이 있다. 이 중 LCoS projection display 제작을 위한 첫 단계인 유리기판은 가시광선 영역에서 96% 이상의 높은 투과도와 3% 미만의 반사도를 요구하는 기술을 필요로 한다. 본 연구에서는 indium이 doping된 tin oxide (ITO)를 투명 전도성막으로 사용하고, $SiO_2/MgF_2$ 이중 박막을 반사방지막으로 채택하여 고투과도 및 저반사율을 갖는 유리기판 제조에 응용하였다. 먼저 15nm 두께의 ITO 박막을 DC sputtering을 이용하여 8-inch 크기의 corning1737 유리기판 상에 증착한 후, 그 반대편에 e-beam evaporation 장비를 사용하여 120nm 두께의 반사 방지막을 증착하였다. 또한 유리기판 상에 증착된 투명 전도성막의 표면개질을 위하여 Ar plasma를 이용하여 treatment를 수행하였다. 이 때 sputtering 조건은 DC power, Ar 유량 및 압력을 조절함으로서 높은 투과도를 갖는 최적의 조건을 구현하였고, e-beam evaporation을 이용한 반사방지막 증착 조건은 $SiO_2$와 $MgF_2$의 계면에서 빛의 반사를 최소화할 수 있는 최적의 조건을 구현하였다. 제작된 유리기판은 가시광선 영역에서 97% 이상의 투과도를 보였으며, 최대 2.8%의 반사율을 보여, LCoS display 제작에 적합함을 확인할 수 있었다. 또한 Ar plasma 처리 후 ITO 박막의 면저항 값은 $100\;{\omega}/{\Box}$, 표면 거칠기는 rms 값 기준 0.095nm, 접촉각 $20.8^{\circ}$의 특성을 보여, 타 index matched transparent conducting oxide가 coating된 유리기판에 비해 우수한 특성을 보였다.