• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 추계학술대회 논문집
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• pp.29-30
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• 2007

In a device structure of ITO/tris(8-hydroxyquinoline) aluminum $(Alq_3)$/Al device, We investigated an the electrical characteristics of Organic Light-Emitting Diodes (OLEDs) depending on the hole-size of boat. The device was manufactured using a thermal evaporation under a base pressure of $5{\times}10^{-6}$ [Torr]. The $Alq_3$ organics were evaporated to be 100 [nm] thick at a deposition rate of $1.5[{\AA}/s]$, and in order to investigate the optimal surface roughness of $Alq_3$, the $Alq_3$ was thermally evaporated to be 0.8 [mm], 1.0 [mm], 1.5 [mm], and 3.0 [mm] as a hole-size of the boat respectively. We found that when the hole-size of the boat is 1.0 [mm], luminance and external quantum efficiency are superior.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 학술대회 및 기술세미나 논문집 디스플레이 광소자
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• pp.54-55
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• 2006

Organic light-emitting diodes(OLEOs) are attractive because of possible application in display with low operating voltage, low power consumption, self-emission and capability of multicolor emission by the selection of emissive material. We investigated the effects of deposition rate on the electrical characteristics, physical characteristics and optical characteristics of OLEOs in the ITO(indium-tin-oxide)/N.N'-diphenyl-N,N'-bis(3-methyphenyl)-1,1'-biphenyl-4,4'-diamine(TPD)/tris(8-hydroxyquinoline)aluminum($Alq_3$)/Al device. We measured current density, luminous flux and luminance characteristics of devices with varying deposition rates of TPD and $Alq_3$. It has been found that optimal deposition rate of TPD and $Alq_3$ were respectively $1.5{\AA}/s$ from the device structure. An AFM measurement results, surface roughness of the deposited film was the lowest when deposition rate was $1.5{\AA}/s$.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
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• pp.428-429
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• 2006

In this thesis, verifies electrical-optical characteristics of phosphorescent materials. basic structure of fabricating devices is glass/ITO/$\alpha$-NPD($300{\AA}$)/CBP:Guest($300{\AA}$)/BCP($80{\AA}$)/$Alq_3(100{\AA})$/Al($1000{\AA}$). In efficiency, fabrication of organic light emitting diodes using $Ir(btp)_2acac$ phosphorescent material is external quantum efficiency 0.268% as doping concentration 3%. At CIE coordinates, phosphorescent material $Ir(btp)_2acac$ following materials moves high purity red color(x=0.6686, y=0.3243). The brightness shows $285cd/cm^2$.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2005년도 춘계학술대회 논문집 디스플레이 광소자 분야
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• pp.193-196
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• 2005

유기발광소자의 발광층의 두께에 따른 임피던스의 변화를 살펴보았다. 임피던스는 두께에 따라 저항의 변화에 따른 의존성을 보이며, 그에 따른 임피던스와 Cole-Cole 반원의 변화, 두께에 따른 $1/\tau$ 의 변화를 살펴보았다. 발광층의 두께는 각각 100, 200, 300 nm의 두께로 열증착하여 실험하였고, 소자의 구조는 $ITO/Alq_3/Al$의 구조로 측정 하였다. 유기발광소자의 발광층인 $Alq_3$의 두께가 증가함에 따라 임피던스의 크기가 증가하고, 위상각의 크기는 100nm의 경우 0V에서 용량성을 보이다가 6~10V까지 부성저항특성을 나타낸 후 약 22V에서 저항성을 나타내고, 200과 300 nm의 경우 12V까지 용량성을 나타내다 이후 22V 근방에서 $0^{\circ}$에 가까워지며 저항성을 나타내는 것을 알 수 있었다. 또한 두께에 따른 Cole-Cole 반원을 살펴보면 두께가 증가할수록 반원의 크기가 증가하는 것을 알 수 있으며, 이를 통해 간단한 등가회로를 예측할 수 있었다. 그리고 벌크내의 용량성$(C_p)$을 측정하여 두께의 증가에 따라 $C_p$ 값이 감소하는 것을 알 수 있었다.

• 한국전기전자재료학회논문지
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• 제20권4호
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• pp.357-362
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• 2007

AZO(Aluminum-doped Zinc Oxide) films are attractive materials as transparent conductive electrode because they are inexpensive, nontoxic and abundant element compared with ITO(Indium Tin Oxide). AZO films have been deposited on glass (corning 1737) substrates by RF magnetron sputtering. The AZO film was post-annealed at $600^{\circ}C$ for 2 hr with $N_2$ atmosphere. The AZO films were used as an anode contact to fabricate OLEDs(Organic Light Emitting Diodes). OLEDs with $AZO/TPD/Alq_3/Al$ configuration were fabricated by thermal evaporation. We investigated that the electric, structural and optical properties of AZO thin films, which measured using the methods of XRD, SEM, Hall measurement and Spectrophotometer. The current density-voltage and luminescence-voltage properties of devices were studied and compared with ITO devices fabricated under the same conditions.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 추계학술대회 논문집
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• pp.412-413
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• 2007

We report on the electrical, optical, and structural properties of indium zinc tin oxide (IZTO) anode films grown at room temperature on glass substrate. The IZTO anode films grown by a RF magnetron sputtering were investigated as functions of RF power, working pressure, and process time in pure Ar ambient. To investigate electrical, optical and structural properties of IZTO anode films, 4-point probe, Hall measurement, UV/Vis spectrometer, Field Emission Scanning Electron Microscopy (FE-SEM), and X-ray diffraction (XRD) were performed, respectively. A sheet resistance of $13.88\;{\Omega}/{\square}$, average transmittance above 80 % in visible range were obtained from optimized IZTO anode films grown on glass substrate. These results shown the amorphous structure regardless of RF power and working pressure due to low substrate temperature.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.401-402
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• 2007

The preparation and characteristics of ITO anode films grown using a linear facing target sputtering (FTS) technique for use in organic light emitting diodes (OLED) and flexible OLED is described. The electrical, optical, and work function of the ITO anode, which was prepared by linear FTS at room temperature, were comparable to those of commercial ITO anode films. In particular, linear FTS-grown ITO films shows very smooth surface without defects such as pin hole and cracks due to low substrate temperature. Furthermore OLED with the linear FTS-grown ITO anode film shows comparable electrical and optical properties to those of OLED with the commercial crystalline-ITO anode film. This suggested that linear FTS is promising thin film technology for preparing high quality anode film in OLEDs and flexible OLEDs.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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• pp.207.2-207.2
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• 2013

Oxide-based thin film transistors have been attempted as powerful candidates for driving circuits for active-matrix organic light-emitting diodes and transparent electronics. The oxide TFTs are based on the amorphous multi-component oxides involving zinc, indium, and/or tin elements as main cation sources. The current work employed RF sputtering in order to deposit zinc-tin oxide thin films applicable to transparent oxide thin film transistors. The deposited thin film was characterized and probed in terms of materials and devices. The physical/chemical characterizations were performed using X-ray diffraction, Atomic Force Microscopy, Spectroscopic Ellipsometry, and X-ray Photoelectron Spectroscopy. The thin film transistors were fabricated using a bottom-gated structure where thermally-grown silicon oxide layers were applied as gate-dielectric materials. The inherent properties of oxide thin films are combined with the corresponding device performances with the aim to fabricating the multi-component oxide thin films being optimized towards transparent electronics.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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• pp.129.2-129.2
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• 2013

Electron injection enhancement at OLED (organic light-emitting diodes) cathode side has mostly been achieved by insertion of a low work function layer between metal electrode and emissive layer. We investigated the interfacial chemical reactions and electronic structures of alkaline-earth metal (Ca, Ba)/Alq3 [tris(8-hydroxyquinolinato)aluminium] and Ca/BaF2/Alq3 using in-situ X-ray & ultraviolet photoelectron spectroscopy. The alkaline-earth metal deposited on Alq3 generates two energetically separated gap states in sequential manner. This phenomenon is explained by step-by-step charge transfer from alkali-earth metal to the lowest unoccupied molecular orbital (LUMO) states of Alq3, forming new occupied states below Fermi level. The BaF2 interlayer initially prevents from direct contact between Alq3 and reactive Ca metal, but it is dissociated into Ba and CaF2. However, as the Ca thickness increases, the Ca penetrates the interlayer to directly participate in the reaction with underlying Alq3. The influence of the multiple gap state formation by the interfacial chemical reaction on the OLED performance will be discussed.

• 패션비즈니스
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• 제25권4호
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• pp.125-140
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• 2021

Recently, flexible displays have been used as part of fashion beyond the concept of parts for electronic products. The flexible display applied to wearable fashion products flexibly bends according to the wearing position of the human body and, at the same time, decorates the fashion product more splendidly through the screen on which images or videos are displayed. Flexible displays, which are used for clothes and accessories, combine analogue fashion sensibility with digital screens to create a new level of convergence product design and expand the range of fashion design and fashion materials. This study aims to analyze the trends of the development and commercialization of fashion products that use flexible displays. As a research method, theoretical research and empirical research through case analysis were conducted in parallel. First, as a theoretical study, the morphological and technical characteristics of flexible displays were examined. Through theoretical studies, the effect of the characteristics of flexible displays on the development of wearable fashion products was investigated. Second, as an empirical case study, the design of wearable fashion products using flexible displays over the past 10 years and the characteristics of the displays used in the products were analyzed. Based on the characteristics analyzed, the product design, display and product integration methods and the commercialization stages of wearable fashion products using flexible displays were analyzed.