• 한국재료학회:학술대회논문집
• /
• 한국재료학회 2003년도 추계학술발표강연 및 논문개요집
• /
• pp.200-200
• /
• 2003

Polycrystalline Si(polysilicon) TFTs have opened a way for the next generation of display devices, due to their higher mobility of charge carriers relative to a-Si TFTs. The polysilicon W applications extend from the current Liquid Crystal Displays to the next generation Organic Light Emitting Diodes (OLED) displays. In particular, the OLED devices require a stricter control of properties of gate oxide layer, polysilicon layer, and their interface. The polysilicon layer is generally obtained by annealing thin film a-Si layer using techniques such as solid phase crystallization and excimer laser annealing. Typically laser-crystallized Si films have grain sizes of less than 1 micron, and their electrical/dielectric properties are strongly affected by the presence of grain boundaries. Impedance spectroscopy allows the frequency-dependent measurement of impedance and can be applied to inteface-controlled materials, resolving the respective contributions of grain boundaries, interfaces, and/or surface. Impedance spectroscopy was applied to laser-annealed Si thin films, using the electrodes which are designed specially for thin films. In order to understand the effect of grain size on physical properties, the amorphous Si was exposed to different laser energy densities, thereby varying the grain size of the resulting films. The microstructural characterization was carried out to accompany the electrical/dielectric properties obtained using the impedance spectroscopy, The correlation will be made between Si grain size and the corresponding electrical/dielectric properties. The ramifications will be discussed in conjunction with active-matrix thin film transistors for Active Matrix OLED.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
• /
• pp.209.2-209.2
• /
• 2013

We proposed and fabricated zinc oxide thin-film transistors (TFTs) employing 4-mercaptophenol (4MP) doped ZnO by atomic layer deposition (ALD) that results in highly stable and high performance. The 4MP concentration in ZnO films were varied from 1.7% to 5.6% by controlling Zn:4MP pulses. The n-type carrier concentrations in ZnO thin films were controlled from $1.017{\times}10^{20}/cm^3$ to $2.903{\times}10^{17}/cm^3$ with appropriate amount of 4MP doping. The 4.8% 4MP doped ZnO TFT revealed good device mobility performance of 8.4 $cm^2/Vs$ and the on/off current ratio of 106. Such 4MP doped ZnO TFTs exhibited relatively good stability (${\Delta}V_{th}$: 2.4 V) under positive bias-temperature stress while the TFTs with only ZnO showed a 4.3 ${\Delta}V_{th}$ shift, respectively.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
• /
• pp.1027-1029
• /
• 2004

In this paper, we have fabricated pentacene thin film transistors (TFTs) using polyvinylphenol (PVP) copolymer and cross-linked PVP as gate insulator on glass and plastic (PET) substrate. Depending on the density of PVP and cross-link material the performance has been changed. We obtained the best device performance with the mobility of 0.32cm2/V${\cdot}$sec and the on/off current ratio of 1.19${\times}$106 for the case of 10wt% PVP copolymer mixed with 5wt% poly (melamine-co-formaldehyde). Additionally using pentacene TFTs with the above PVP gate insulator, we fabricated the integrated circuits including inverter which produced the gain of 9.7.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2002년도 하계학술대회 논문집 C
• /
• pp.1590-1592
• /
• 2002

In this work the electrical characteristics of organic TFTs using organic insulator and flexible polyester substrate have been investigated. Pentacene and PVP(polyvinylphenol) are used as an active semiconducting layer and dielectric layer respectively. Pentacene was thermally evaporated in vacuum at a pressure of about $1{\times}10^{-6}$ Torr and at a deposition rate of $0.5{\AA}$/sec, and PVP was spin-coated. Aluminium and gold were used for gate and source/drain electrodes. 0.1mm thick flexible polyester substrate was used instead of glass or silicon wafer.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
• /
• pp.785-789
• /
• 2005

Low temperature deposition of silicon and silicon nitride films by catalytic CVD technique was studied for application to thin film transistors on plastic substrates for flexible AMOLEDs. The substrate temperature initially held at room temperature, and was controlled successfully below $150^{\circ}C$ during the entire deposition process. Amorphous silicon films having good adhesion, good surface morphology and sufficiently low content of atomic hydrogen were obtained and could be successfully crystallized using excimer laser without a prior dehydrogenation step. $SiN_x$ films showed a good refractive index, a high deposition rate, a moderate breakdown field and a dielectric constant. The Cat-CVD silicon and silicon nitride films can be good candidates for fabricating thin films transistors on plastic substrates to drive active-matrix organic light emitting display.

• 한국전자통신학회논문지
• /
• 제14권1호
• /
• pp.87-96
• /
• 2019

유기 박막 트랜지스터 (OTFT) 백플레인을 이용한 유연한 유기 발광 다이오드 (OLED) 디스플레이가 연구되고 있다. OLED 디스플레이의 구동을 위해서 게이트 드라이버가 필요하다. 저온, 저비용 및 대 면적 인쇄 프로세스를 사용하는 디스플레이 패널의 내장형 게이트 드라이버는 제조비용을 줄이고 모듈 구조를 단순화한다. 이 논문에서는 유연한 OLED 디스플레이 패널의 내장형 게이트 드라이버 제작을 위하여 OTFT를 사용한 의사 CMOS (pseudo complementary metal oxide semiconductor) 로직 게이트를 구현한다. 잉크젯 인쇄형 OTFT 및 디스플레이와 동일한 프로세스를 사용하여 유연한 플라스틱 기판 상에 의사 CMOS 로직 게이트가 설계 및 제작되며, 논리 게이트의 동작은 측정 실험에 의해 확인된다. 최대 1 kHz의 입력 신호 주파수에서 의사 CMOS 인버터의 동작 결과를 통하여 내장형 게이트 드라이버의 구현 가능성을 확인하였다.

• 한국전기전자재료학회논문지
• /
• 제16권11호
• /
• pp.961-968
• /
• 2003

In order to reach the high electrical quality of organic thin film transistors (OTFTs) such as high mobility and on-off current ratio, it is strongly desirable to study the enhancement of electrical properties in OTFTs. Here, we report the novel method of hydrogen plasma treatment to improve electrical properties in inverted staggered OTFTs based on pentacene as active layer. To certify the effect of this method, we compared the electrical properties of normal device as a reference with those of device using the novel method. In result, the normal device as a reference making no use of this method exhibited a field effect mobility of 0.055 $\textrm{cm}^2$/Vs, on/off current ratio of 10$^3$, threshold voltage of -4.5 V, and subthreshold slope of 7.6 V/dec. While the device using the novel method exhibited a field effect mobility of 0.174 $\textrm{cm}^2$/Vs, on/off current ratio of 10$\^$6/, threshold voltage of -0.5 V, and subthreshold slope of 1.49 V/dec. According to these results, we have found the electrical performances in inverted staggered pentacene TFT owing to this method are remarkably enhanced. So, this method plays a key role in highly improving the electric performance of OTFTs. Moreover, this method is the first time yet reported for any OTFTs.

• 마이크로전자및패키징학회지
• /
• 제14권1호
• /
• pp.27-31
• /
• 2007

휨성 유기박막트랜지스터(organic thin film transistor, OTFT)를 제작하기 위하여 게이트 절연막으로 PVP(poly-4-vinylphenol) 유기막을 이용하여 MIM (metal-insulator-metal) 구조의 캐패시터 소자를 제작하였다. 유기 절연층의 형성은 Al/PES (polyethersulfone) 기판과 ITO/Glass 기판 위에 PVP를 용질로, PGMEA(propylene glycol monomethyl ether acetate)를 용매로 사용하였다 또한 열경화성 수지인 poly(melamine-co-(ormaldehyde)를 사용하여 cross-linked PVP 절연막을 합성하여 스핀코팅법으로 소자를 형성하였다. 제작된 소자에 대해 절연막 두께와 기판 종류에 따른 전기적 특성을 조사한 결과 Al/PES 기판을 사용하였을때 누설전류는 1.3 nA로 ITO/glass 기판을 사용했을때의 27.5 nA보다 크게 개선되었다. 또한 제작된 모든 캐패시터 소자의 정전용량은 $1.0{\sim}1.2nF/cm^2$ 범위로 나타났으며 계산값과 매우 유사한 결과를 얻을 수 있었다.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2011년도 제40회 동계학술대회 초록집
• /
• pp.473-473
• /
• 2011

In recent years, organic thin film transistors OTFTs based on conductive-conjugated molecules have received significant attention. We report a fabrication of organic single crystal nanowires that made on Si substrates by liquid bridge-mediated nanotransfer molding (LB-nTM) with polyurethane acrylate (PUA) mold. LB-nTM is based on the direct transfer of various materials from a stamp to a substrate via a liquid bridge between them. In liquid bridge-transfer process, the liquid layer serves as an adhesion layer to provide good conformal contact and form covalent bonding between the organic single crystal nanowire and the Si substrate. Pentacene is the most promising organic semiconductors. However pentacene has insolubility in organic solvents so pentacene OTFTs can be achieved with vacuum evaporation system. However 6, 13-bis (triisopropylsilylethynyl) (TIPS) pentacene has high solubility in organic solvent that reported by Anthony et al. Furthermore, the substituted rings in TIPS-pentacene interrupt the herringbone packing, which leads to cofacial ${\pi}-{\pi}$ stacking. The patterned TIPS-Pentacene single crystal nanowires have been investigated by Atomic force microscopy (AFM), Transmission Electron Microscopy (TEM), X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and electrical properties.

• 공업화학
• /
• 제35권1호
• /
• pp.61-65
• /
• 2024

대면적 유기 발광 다이오드, 유기 태양 전지, 박막 트렌지스터의 정공 주입층으로써 CuSCN의 효과가 많이 입증되었다. 따라서 본 연구에서는 용액 공정 조건에 따라 CuSCN의 표면과 광학적, 전기적 분석을 하여 최적화된 필름의 조건을 제시하였다. 다양한 CuSCN 용액의 농도를 제작하여 필름 표면 특성을 확인하였고, 필름의 표면이 소자의 전기적 성능에 영향을 미치는지 확인하였다. CuSCN의 용액의 농도가 낮을 때는 CuSCN의 필름이 형성되지 않고 island 형태로 코팅되었고, 용액의 농도가 증가할수록 CuSCN의 필름이 균일하게 형성하였고 이는 소자의 전도도 향상에 기여하였다. 또한 hole only device를 제작하여 CuSCN의 정공 수송 층으로써의 역할을 입증하였다.