• JSTS:Journal of Semiconductor Technology and Science
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• 제9권1호
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• pp.51-54
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• 2009

Transparent Cuprous oxide film was deposited by rapid thermal oxidation (RTO) of Cu at $500^{\circ}C$/45s condition on textured single-crystal n-Si substrate to form $Cu_2O$/n-Si heterojunction photodiode. The Hall effect measurements for the $Cu_2O$ films showed a p-type conductivity. The photovoltaic and electrical properties of the junction at room temperature were investigated without any post-deposition annealing. I-V characteristics revealed that the junction has good rectifying properties. The C-V data showed abrupt junction and a built-in potential of 1 V. The photodiode showed good stability and high responsivity in the visible at three regions; 525 nm, 625-700 nm, and 750nm denoted as regions A, B, and C, respectively.

• JSTS:Journal of Semiconductor Technology and Science
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• 제8권1호
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• pp.40-45
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• 2008

We developed small molecular organic nonvolatile $4F^2$ memory cells using metal layer evaporation followed by $O_2$ plasma oxidation. Our memory cells sandwich an upper ${\alpha}$-NPD layer, Al nanocrystals surrounded by $Al_2O_3$, and a bottom ${\alpha}$-NPD layer between top and bottom electrodes. Their nonvolatile memory characteristics are excellent: the $V_{th},\;V_p$ (program), $V_e$ (erase), memory margin ($I_{on}/I_{off}$), data retention time, and erase and program endurance were 2.6 V, 5.3 V, 8.5 V, ${\approx}1.5{\times}10^2,\;1{\times}10^5s$, and $1{\times}10^3$ cycles, respectively. They also demonstrated symmetrical current versus voltage characteristics and a reversible erase and program process, indicating potential for terabit-level nonvolatile memory.

• 한국전기전자재료학회논문지
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• 제28권8호
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• pp.496-500
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• 2015

This paper was proposed the theoretical research and optimal design 3000V super junction NPT IGBT for using electrical automotive and power conversion. Because super junction IGBT was showed ultra low on resistance, it was structure that can improve the thermal characteristics of conventional NPT IGBT. The electrical characteristics of super junction NPT IGBT were 2.52 V of on state voltage drop, 4.33 V of threshold voltage and 2,846 V breakdown voltage. We did not obtaing 3,000 V breakdown voltage but we will obtain 3,000 V breakdown voltage through improving p pillar layer. If we are carried this research, This device will be used electrical automotive, power conversiton and high speed train.

• 한국의학물리학회지:의학물리
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• 제25권3호
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• pp.185-192
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• 2014

이 연구의 목적은 본원이 보유하고 있는 선형가속기들의 출력 특성을 Shewhart-type Chart, EWMA Chart, 공정능력지수 $C_p$와 $C_{pk}$을 이용한 통계적 분석으로 품질보증에 대한 결과를 평가하고자 한다. 측정값은 의학물리사에 의하여 2012년 9월부터 2014년 4월까지 매월 측정된 각각 치료기들(21EX, 21EX-S, Novalis Tx)의 출력측정값을 사용하였다. 치료기들의 출력 특성은 IAEA TRS-398의 가이드라인을 따랐으며, 측정 에너지는 광자선 6 MV, 10 MV, 15 MV와 전자선 4 MeV, 6 MeV, 9 MeV, 12 MeV, 16 MeV, 20 MeV였다. 매월 측정하여 교정한 출력특성에 대한 통계학적 분석이며, 가중인자와 측정값의 관리한계의 폭은 ${\lambda}=0.10$, L=2.703로 계산되었으며, 공정능력 $C_p$와 $C_{pk}$는 모든 선형가속기(21EX, 21EX-S, Novalis Tx)의 모든 에너지에서 1이상이었다. Shewhart-type Chart를 통하여 출력선량의 측정값의 큰 변화점을 찾을 수 있었고, EWMA Chart를 통하여 출력선량의 측정값의 미세한 변화점을 알아 볼 수 있었다. 본원의 치료기의 공정능력지수 $C_p$와 $C_{pk}$를 통하여 21EX가 2.384와 2.136, 21EX-S가 1.917과 1.682, Novalis Tx가 2.895와 2.473으로 Novalis Tx가 가장 안정적이고 정확한 출력특성을 나타내고 있었다.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제51권6호
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• pp.229-235
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• 2002

This paper presents the fabrication of polycrystalline thin film transistor(TFT) using sequential lateral solidification(SLS) of amorphous silicon. The fabricated SLS TFT showed high Performance suitable for active matrix liquid crystal display(AMLCD). The SLS process involves (1) a complete melting of selected area via irradiation through a patterned mask, and (2) a precisely controlled pulse translation of the sample with respect to the mask over a distance shorter than the super lateral growth(SLG) distance so that lateral growth extended over a number of iterative steps. The SLS experiment was performed with 550$\AA$ a-Si using 308nm XeCl laser having $2\mu\textrm{m}$ width. Irradiated laser energy density is 310mJ/$\textrm{cm}^2$ and pulse duration time was 25ns. The translation distance was 0.6$\mu$m/pulse, 0.8$\mu$m/pulse respectively. As a result, a directly solidified grain was obtained. Thin film transistors (TFTs) were fabricated on the poly-Si film made by SLS process. The characteristics of fabricated SLS p -type poly-Si TFT device with 2$\mu\textrm{m}$ channel width and 2$\mu\textrm{m}$ channel length showed the mobility of 115.5$\textrm{cm}^2$/V.s, the threshold voltage of -1.78V, subthreshold slope of 0.29V/dec, $I_{off}$ current of 7$\times$10$^{-l4}$A at $V_{DS}$ =-0.1V and $I_{on}$ / $I_{off}$ ratio of 2.4$\times$10$^{7}$ at $V_{DS}$ =-0.1V. As a result, SLS TFT showed superior characteristics to conventional poly-Si TFTs with identical geometry.y.y.y.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 춘계학술대회 논문집 전기설비전문위원
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• pp.31-34
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• 2005

The 765kV transmission line will be maintained by live-line works for efficient operation, In order to maintain the 765kV transmission lines safely by live-line works, lineman have to know flashover characteristics of the insulator strings with damaged insulators. This paper suggests flashover characteristics of the 765kV insulator strings from experimental test results directly.

• 대한기계학회논문집
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• 제16권10호
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• pp.1890-1899
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• 1992

본 연구에서는 이종재료간의 Ⅴ-노치균열의 노치각도 및 재료의 종류에 따른 응력특이성지수와 응력강도 계수 해석에 각각 뉴톤-랍슨법(newtonraphson method), 뉴톤-랍슨법과 최소자승법을 이용한 선점법(collocation method)인 수치해석적 방법을 응용하고, 광탄성 등색선 무늬를 컴퓨터 그래픽하여 응력특이성지수와 응력강도계수가 모우드(mode)에 미치는 특성과 경계요소법(boundary element method)으로 응력해석한 결과로써 선점법을 이용하여 응력강도계수를 해석하고 기존의 결과등과 비교, 검토하 고자 한다.

• 한국재료학회지
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• 제12권6호
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• pp.464-469
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• 2002

$SrBi_2Nb_2O_9(SBN)$ thin films were grown on Pt/Ti/Si and p-type Si(100) substrates by rf-magnetron co-sputtering method using two ceramic targets, $SrNb_2O_6\; and \;Bi_2O_3$. The structural and electrical characteristics have been investigated to confirm the possibility of the SBN thin films for the applications to destructive and nondestructive read out ferroelectric random access memory(FRAM). For the optimum growth condition X-ray diffraction patterns showed that SBN films had well crystallized Bi-layered perovskite structure after $700^{\circ}C$ heat-treatment in furnace. From this specimen we got remnant polarization $(2P_r)$ of about 6 uC/$\textrm{cm}^2$ and coercive voltage $(V_c)$ of about 1.5 V at an applied voltage of 5 V. The leakage current density was $7.6{\times}10^{-7}$/A/$\textrm{cm}^2$ at an applied voltage of 5V. And for the NDRO-FRAM application, properties of SBN films on Si substrate has been investigated. From transmission electron microscopy (TEM) analysis, we found the furnace treated sample had a native oxide about 2 times thicker than the RTA treated sample and this thick native oxide layer had a bad effect on C-V characteristics of SBN/Si thin film. After $650^{\circ}C$ RTA process, we got the improved memory window of 1.3 V at an applied voltage of 5 V.

• 전자공학회논문지D
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• 제36D권10호
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• pp.31-36
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• 1999

질소 화합물의 새로운 형광체를 개발하기 위하여 $CaSiN_2:Eu,\;CaSiN_2:Tb$ 형광체를 합성한 후, 빛 발광 (photoluminescence, PL) 및 전계 발광(electroluminescence, EL) 특성을 평가하였다. $Ca_3N_2$, $Si_3N_4$ 및 $EuF_3$ 또는 $TbF_3$의 미분말을 혼합, 성형 및 소결하여 질소 화합물 형광체를 합성하였다. 합성된 $CaSiN_2:Eu,\;CaSiN_2:Tb$ 형광체의 PL 특성이 각각 Eu, Tb 이온에 의한 고유한 발광 파장과 일치하여 형광체로의 활용 가능성을 확인하였다. 스퍼터링 방법으로 제작된 $CaSiN_2:Eu$ 박막 전계 발광(thin-film electroluminescence, TFEL) 소자의 문턱 전압과 280 V에서의 발광 휘도는 각각 90 V, 1.62 $cd/m^2$ 임을 알 수 있었다. 또한 change-voltage(Q-V) 및 transferred charge-phosphor Field($Q_t-F_p$)의 전기적 특성도 함께 측정되었다.

• 전기학회논문지P
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• 제58권4호
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• pp.602-608
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• 2009

In this thesis, output voltage, current and power of solar module were classified by irradiation from data of overall operating characteristics collected for one year in order to manage efficient photovoltaic generation system and deliver maximum power. In addition, from these data, correlations between irradiation of photovoltaic cell and amount of power given by photovoltaic cell was quantitatively examined to deduce optimization of the design and construction of photovoltaic generation system. As I-V characteristics according to a temperature range of 10~50[$^{\circ}C$], the area of I-V characteristics were increased with an increase in temperature. Since this area corresponds to the power, output power is thought to have increased with temperature. As output power characteristics according to a temperature range of 10~50[$^{\circ}C$], output power was increased with an increase in temperature. Since output power increases with temperature increase, the result corresponds well to the related equation on temperature and output power. As I-V characteristics according to a irradiation range of 100~900 [$W/m^2$], voltage and current were increased with an increase in irradiation. The result is thought of as an increase in output power with increasing irradiation. As output power characteristics according to a irradiation range of 100~900 [$W/m^2$], output power was increased with increasing irradiation. This result corresponds well to the related equation on irradiation and output power.