• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 추계학술대회 논문집 학회본부 C
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• pp.792-794
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• 1998

The TPD and the $Alq_3$ film are widely used as a hole transport layer and an emitter layer respectively, in organic electroluminescent(EL) device (ITO Glass/TPD/$Alq_3$/metal). In this structure, we fabricated two models. Model(1) having ITO glass/$Alq_3$/Al structure and model(2) having ITO Glass/TPD/$Alq_3$/Al structure were fabricated by the vacuum evaporation. The comparison between model(1) and model(2) was made about the absorbance, the wave length, the current-voltage characteristic and the ln I - $V^{(1/2)}$characteristic respectively. Electroluminescence of green and wavelength of 510[nm] were observed in both model. We observed absorbance from 320[nm] to 430[nm] in $Alq_3$ material and from 250[nm] to 400[nm] in TPD material.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.II
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• pp.1536-1537
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• 2005

We have made point electron sources using carbon nanotubes (CNTs). For the fabrication of point electron sources, CNTs were dispersed in a solution and attached on electrochemically etched W tips using electrophoresis. In our study, we have utilized various CNTs such as single-walled CNT (SWCNT), multiwalled CNT (MWCNT), and thin-MWCNT and threshold current, turn-on voltage, filed enhancement factor of each emitter have been studied upon a tube/bundle diameter and length. In addition, fieldemitted electron energy distribution of various CNT emitters is characterized.

• 한국전기전자재료학회논문지
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• 제23권4호
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• pp.273-279
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• 2010

In this paper, we proposed 2500 V Non punch-through(NPT) Insulated gate bipolar transistor(IGBT) for high voltage industry application. we carried out optimal simulation for high efficiency of 2500 V NPT IGBT according to size of device. In results, we obtaind design parameter with 375 um n-drift thickness, 15 um gate length, and 8um emitter windows. After we simulate with optimal parameter, we obtained 2840 V breakdown voltage and 3.4V Vce,sat. These design and process parameter will be used designing of more 2000 V NPT IGBT devices.

• 대한전자공학회논문지
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• 제27권10호
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• pp.89-95
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• 1990

동작 속도와 용량성 부하에 따른 최적소자크기를 결정할 수 있는 bipolar-CMOS 버퍼 모델을 제안한다. 면적 최적화를 위한 해석적 결과를 바이폴라의 고주입 효과 및 MOS의 챠넬 속도제한영역을 가정하여 구했다. BICMOS 버퍼의 면적은 용량성 부하에 거의 비례하는 에미터 길이와 챠넬 폭을 정함으로써 최적화된다는 것을 보이고, 회로 세뮬레이션 결과와 비교하여 확인하였다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 추계종합학술대회 논문집(2)
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• pp.245-248
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• 2000

In this paper, we present a high-performance SiGe HBT's RF input impedance parameter extraction method. The SiGe HBT has emitter width of 0.5${\mu}{\textrm}{m}$ and length of 6${\mu}{\textrm}{m}$. S-parameter has been measured with the collector current of 1~3㎃ using on-wafer RF measuring system . The pre-calculation method was used in order to overcome the local minimum problem. This method enabled us to extract a RF(1~10㎓) input impedance parameter.

• 전자공학회논문지D
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• 제35D권4호
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• pp.84-92
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• 1998

A program was developed to analyze the electrical characteristics and harmonic distrotion in a two-dimensional silicon BJT. The finite difference equations of the small signal and its second and thired harmonics for basic semiconductor equations are formulated treating the nonlinearity and time dependence with Volterra series and Taylor series. The soluations for three sets of simultaneous equations were obtained sequantially by a decoupled iteration method and each set was solved by a modified Stone's algorithm. Distortion magins and ac parameters such as input impedance and current gains are calculated with frequency and load resistance as parameters. The distortion margin vs. load resistancecurves show cancellation minima when the pahse of output voltage shifts. It is shown that the distortionof small signal characteristics can be reduced by reducing the base width, increasing the emitter stripe length and reducing the collector epitaxial layer doping concentration in the silicon BJT structure. The simulation program called TRADAP can be used for the design and optimization of transistors and circuits as well as for the calculation of small signal and distortion solutions.

• 세라미스트
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• 제21권1호
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• pp.98-111
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• 2018

The lead-based perovskite (CH3NH3PbI3) material has a high molar coefficient, high crystallinity at low temperature, and long range of balanced electron-hole transport length. In addition, PCE of perovskite solar cells (PSCs) has been dramatically improved by over 22% by amending the electronic quality of perovskite and by using state-of-the-art hole transporting materials (HTMs) such as tetrakis(N,N-di-p-methoxyphenylamine)-9,9'-spirobifluorene (spiro-OMeTAD) due to enhanced charge transport toward the electrode via properly aligned energy levels with respect to the perovskite. Replacing the spiro-OMeTAD with new HTMs with the desired properties of appropriate energy levels, high hole mobility in its pristine form, low cost, and easy processable materials is necessary for attaining highly efficient and stable PSCs, which are anticipated to be truly compatible for practical application. Furthermore, Recently Pb-free perovskite materials much attention as an alternative light-harvesting active layer material instead of lead based perovskite in photovoltaic cells. In this work, we demonstrate a Pb-free perovskite material for the light harvesting and emitter as optoelectronic devices.

• 마이크로전자및패키징학회지
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• 제8권1호
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• pp.13-18
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• 2001

본 연구에서 RF 플라즈마를 이용한 촉매 화학기상증착법에 의하여 탄소나노튜브를 성장시켰다. 탄소나노튜브는 Ni이 증착된 강화 유리 기판위에 $600^{\circ}C$ 이하의 공정 온도에서 성장되었으며, 성장시 성장 온도와 에칭 시간 그리고 Ni 층의 두메에 따라 탄소나노튜브 성장 특성이 다양하게 나타났다. Ni이 증착된 강화 유리기판위에 탄소나노튜브를 성장시키기 위하여 에칭 가스로는 $H_2$와 $NH_3$가스를 사용하였고, 탄소 원료로 $C_2H_2$가스를 사용하였다. 수직 배향된 탄소나노튜브의 직경과 길이는 약 150 nm와 3 $\mu\textrm{m}$ 정도의 크기로 성장되었다. 촉매 화학기상증착법을 이용하여 성장된 탄소나노튜브는 FED의 에미터로 사용이 기대된다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.1218-1219
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• 2008

Thin films (< 30 nm) of titanium carbide (TiC) are coated on carbon nanotubes (CNTs), which are directly grown on nano-sized ($\sim$ 500 nm in diameter) conical-type tungsten (W) tips, by employing an inductively coupled plasma-chemical vapor deposition (ICP-CVD) technique. Any modification in structural properties (such as length to diameter ratio, crystal quality, and growth behavior) of CNTs due to TiC-coating has been monitored by using high-resolution TEM, field-emission SEM, and Raman spectroscopy. Driving voltage for obtaining the same level of emission current in CNTs-emitter is significantly reduced by TiC-coating. It is also worthy of being noted that the degradation of emission current due to prolonged operation (up to 30 h) is remarkably suppressed by TiC-coating.

• Bulletin of the Korean Chemical Society
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• 제29권2호
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• pp.335-338
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• 2008

New efficient red emitter having short p?-conjugation length and asymmetric bulky structure, 2-(7-diphenylamino-benzo[1,2,5]thiadiazole-4-ylmethylene)-malononitrile, was synthesized and characterized. Using this material as a dopant, we fabricated electroluminescence device with a structure of ITO/DNTPD/NPD/BTZA (5 wt% in Alq3)/Alq3/LiF/Al. The device exhibited a high brightness of 761 cd/m2 at a driving voltage of 4.8 V, and current efficiency is 0.75 cd/A. The Commission International de IEclairage (CIE) coordinates of the EL device were found to be (0.62, 0.37) at 10 mA/cm2.