• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
• /
• pp.1305-1307
• /
• 2009

We have investigated the new modification of poly (vinyl phenol) (PVP) for low hysteresis organic thin film transistors (OTFTs). In order to suppression of hysteresis phenomenon, synthesized various backbone structure polymeric gate dielectric. The modified polymeric dielectric was synthesized by inducing ringshape phenol backbone structure instead of conventional chain. We could be observed that relieved hysteresis and excellent air stability from ring-shape phenol backbone structure.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2000년도 하계학술대회 논문집 C
• /
• pp.1754-1756
• /
• 2000

Organic semiconductors based on fused-ring polycyclic aromatic hydrocarbon have great potential to be utilized as an active layer for electronic and optoelectronic devices. In this study, pentacene thin films and electrode materials were deposited by Organic Molecular Beam Deposition(OMBD) and vacuum evaporation respectively. For the gate dielectric, polyamic acid was spin-coated and cured into polyimide at 350$^{\circ}C$. Electrical characteristics of the devices were investigated, where the channel length and width was 50${\mu}m$ and 5mm. It was found that field effect mobility was 0.012$cm^{2}/Vs$, and on/off current ratio was $10^5$.

• Applied Microscopy
• /
• 제21권1호
• /
• pp.108-120
• /
• 1991

Principles of electron diffraction patterns in transmission electron microscope are described for beginners in terms of reciprocal lattices and Ewald sphere. Analysis of both ring patterns and spot patterns are illustrated with practical examples as well as basic calibrations of TEM. Especially convergent beam electron diffraction method is emphasized for the determination of lattice parameters, microstrains, and thickness of thin foil followed by a review of microcomputer programs for the electron diffraction analyses explained in this paper.

• 한국자기학회:학술대회 개요집
• /
• 한국자기학회 2002년도 동계연구발표회 논문개요집
• /
• pp.186-187
• /
• 2002

Recently, there has been much interest in magnetic thin film patterned in submicron scale because of possible ultrahigh density storage media or logical device applications [1-3]. Various geometries such as rectangle, circle, ring and ellipse type dots have been studied to find the shape showing stable switching behavior from repeated cycles. However, rectangle and circle types may not be suitable for device applications because they have two uncontrollable different magnetization reversal modes: C state and S state, resulting in different coercivity and irreproducible switching[4]. (omitted)

• Journal of Advanced Marine Engineering and Technology
• /
• 제32권8호
• /
• pp.1178-1184
• /
• 2008

In this study, techniques of ion implantation were used in order to improve the characteristics of metal materials such as the oxidation and wear resistant. In particular it is necessary to develope their oxidation and wear resistant that could be used in severe environmental conditions. There are mainly two elementary technologies including ion implantation and/or thin film coating. Ion implantation method was performed for surface modification. As a result, it was found that some ion implantations methods such as Nb, high-temperature Nb ion implantation and Nb+C combined implantation are somewhat effective for improving the oxidation resistance of TiAl alloy. Furthermore, the fluorine PBII treatment is more effective for improving the oxidation resistance of the TiAl alloy with three-dimensional shapes. The implantation of boron ion into thin film of TiN was also effective for improving the properties of materials like high temperature wear resistance. TiCrN film was applied to the actual seal ring for steam turbines, and it was observed that its sliding property showed a successfully good performance.

• 한국재료학회지
• /
• 제18권9호
• /
• pp.507-510
• /
• 2008

Electrical properties of multi-channel metal-induced unilaterally precrystallized polycrystalline silicon thin-film transistor (MIUP poly-Si TFT) devices and circuits were investigated. Although their structure was integrated into small area, reducing annealing process time for fuller crystallization than that of conventional crystal filtered MIUP poly-Si TFTs, the multi-channel MIUP poly-Si TFTs showed the effect of crystal filtering. The multi-channel MIUP poly-Si TFTs showed a higher carrier mobility of more than 1.5 times that of the conventional MIUP poly-Si TFTs. Moreover, PMOS inverters consisting of the multi-channel MIUP poly-Si TFTs showed high dynamic performance compared with inverters consisting of the conventional MIUP poly-Si TFTs.

• 한국진공학회지
• /
• 제5권3호
• /
• pp.245-250
• /
• 1996

$Y_2O_3$ thin film on si(100) was successfully grown by ionized cluster beam(ICBD) technique at substrate temperature of around $500^{\circ}C$ and pressure of ~$10^{-5}$Torr.To prevent the oxidation of Si substrae, a very thin yttrium layer was deposited on Si before reactive depositing of oxygen and yttrium source. In asdeposited stage, b.c.c and h.c.p strucutres of $Y_2O_3$ were observed from S-ary analysis. From the observation of spots and ring patterns in selected area diffractin(SAD) patterns. crystallane formation and growth could be proceeded during the deposition. $Y_2O_3$/mixed layer/$SiO_2=170\AA/50\AA/10\AA$ structure were verified by high resolution transmition electron imcroscopy(HRTEM) image, and the formation of amorphous layer of SiO2 was discussed . Electricla charateristics of the film were also investigated . In as-deposited Pt/$Y_2O_3$/Si sturcuture, leakage current was less than $10^{-6}$A/$\textrm{cm}^2$ at 7MV/cm strength.

• Current Optics and Photonics
• /
• 제1권4호
• /
• pp.372-377
• /
• 2017

We demonstrate that the local resonance of metamaterials can be tuned by the effects of organic thin films under photoexcitation. Tris (8-hydroxyquinolinato) aluminum ($Alq_3$) layers are deposited on metamaterial/silicon hybrid structures. By varying the thickness of the $Alq_3$ layer on the subwavelength scale, the resonant peak of the metamaterial becomes very adjustable, due to the effect of a thin dielectric substrate. In addition, under photoexcitation all the spectral peaks of the resonance shift to higher frequencies. This originates from the reduction of the capacitive response generated inside the gaps of split-ring resonators. The adjustability of the electromagnetic spectrum may be useful for developing optical systems requiring refractive-index engineering and active optical devices.

• 대한화학회지
• /
• 제11권3호
• /
• pp.111-116
• /
• 1967

韓國 山野에 野生하는 참조팝나무 Spiraea Koreana Nakai(Spiraeceae)엽으로 부터 m.p. 182~$184^{\circ}C$의 苦味를 갖인 Alkaloid를 無色 柱狀의 結晶으로 얻었다.(收得率 0.13%). 이 物質은 光學的으로 活性이며(比旋光度$[{\alpha}]d^{19}+3.4^{\circ}$ in $CHCl_3$), Mass Spectrometry에 依해 決定한 分子式은 $C_{23}H_{33}NO_3$이다. 文獻未記載의 것임으로 Spirajine이라 命名하였다. Spiraea Koreane N. 葉 中에는 이 外에도 다른 2種의 알칼로이드가 微量으로 含有되어 있음을 Thin Layer Chromatography로 確認하였으나 結晶으로는 못 얻었다. Spirajine의 部分化學構造에 對해 化學反應, UV, IR, NMR, MS, ORD 等으로 分析檢討함과 아울러 Mass Spectrogram의 Cracking Pattern으로부터의 Fragmentation Analysis의 結果, 分子 中 Cyclohexane 및 Cyclopentane 고리들을 갖으며 그 中 하나는 ${\alpha},{\beta}$ 不飽和 Cyclohexenone고리이고 그 外에 methyl基, 카보닐基, 水酸基, N-Methyl基 等 여러 作用基의 存在를 決定하였다.

• 항공우주기술
• /
• 제2권2호
• /
• pp.124-132
• /
• 2003

본 논문에서는 "KSR-III 복합재 가압탱크“에 대한 구조 설계/제작 과정을 기술하였다. 복합재 가압탱크는 라이너 위에 복합재가 덮어 씌워진 형태이다. 하중을 부담하지 않는 라이너는 AI 6061-0로 만들어 졌으며, 라이너는 헬륨가스 기밀만을 담당하였다. 복합재 탱크는 라이너 위에 T700/Epoxy로 와인딩 하였다. 알루미늄 라이너가 얇았기 때문에 다단계 경화 공정이 필라멘트 와인딩 기법에 적용되었다. 다단계 경화 공정은 라이너의 실린더가 원형 형상을 잃지 않게 하였다. 보스부의 체결력은 보스링에 의하여 카본섬유로 분산되었다. 또한 보스링은 보스부의 국부적 변형을 막았다.