• 공업화학
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• 제23권6호
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• pp.539-545
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• 2012

전자를 끌어당기는 benzotriazole을 vinylene으로 thiophene과 연결한 3-(2-benzo-triazolovinyl)thiophene (BVT)을 합성하고, FT-IR 및 $^1H$-NMR, $^{13}C$-NMR, 2D hetero-cosy spectra로 구조분석을 하였다. 합성한 BVT와 3-octylthiophene (OT)을 공중합 하였다. 공중합체들은 수평균 분자량 12000 (PDI 2.67)과 15000 (PDI 2.55)을 나타내었으며, THF, TCE와 chloroform 등의 유기용매에 잘 용해되었다. 공중합체들의 BVT와 OT의 공중합된 비율은 $^1H$-NMR spectra에 의하여 BVT : OT = 1 : 1.8과 1 : 2.8 (mol/mol)로 확인되었다. 파장 470 nm와 465 nm에서 UV-vis 최대 흡수를 나타내었고, photoluminescence (PL)는 각각 ${\lambda}_{max}$ = 662 nm와 641 nm로 나타나 적색계로 관찰되었다. 공중합체의 band gap은 각각 1.96 eV, 2.02 eV로 poly(3-octylthiophene)보다 더 증가하였다. 또한, poly(3-octylthiophene)에 비해서 HOMO 에너지 준위는 모두 낮아졌으나, LUMO 에너지 준위는 모두 높아졌다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1998년도 추계종합학술대회 논문집
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• pp.545-548
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• 1998

Thin film SOI(Silicon-On-Insulator) devices exhibit floating body effect. In this paper, SOI NMOSFET is proposed to solve this problem. Some part of gate oxide was considered to be 30nm~80nm thicker than the other normal gate oxide and simulated with TSUPREM-4. The I-V characteristics were simulated with 2D MEDICI mesh. Since part of gate oxide has different oxide thickness in proposed device, the gate electric field strength is not the same throught the gate and consequently the reduction of current kink effect is occurred.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권2호
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• pp.1561-1564
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• 2007

$Tb^{3+}-activated$ green-emitting $(Y,Gd)Ga_3(BO_3)_4$ phosphor has been investigated. The main absorption was in the $120{\sim}238$ nm and exhibited a green emission with the 545 nm and several peaks due to inner shell transition of $Tb^{3+}$ ion. With the optimized $Tb^{3+}$ concentrations, the maximum emission brightness was 90% of the $Zn_2SiO_4$:Mn phosphor.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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• pp.530-532
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• 2008

Inorganic metal multi-layer(IMML) consisting of Al/Al:SiO/Al was developed as a cathode for OLED to reduce the reflectance generated from ambient light. Device structure of green OLED was ITO/2-TNATA/$\alpha$-NPD/$Alq_3$:C545T/Balq/$Alq_3$/LiF/IMML and IMML was composed of three different layers: thin aluminum layer, aluminum layer doped with silicon monoxide and thick aluminum layer. Average reflectance of green OLED was 9.63% while that of conventional OLED with or without polarizer showed the average reflectance of 8.54% and 66% respectively at visible range from 380 nm to 780 nm.

• 분석과학
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• 제6권1호
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• pp.57-63
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• 1993

흐름주입법에 의하여 분광광도 방법으로 코발트를 정량하였다. $NH_3-NH_4Cl$ 완충용액(pH 10.5)에서 2-(5-bromo-2-pyridylazo)-5-(N-propyl-N-sulfopropylamino)aniline은 코발트와 수용성 착물을 형성한다. 이 착물의 최대흡수 파장은 545nm이고, 몰흡광계수는 $58000L\;mol^{-1}\;cm^{-1}$이다. 코발트의 검정곡선은 0.1~0.6ppm 범위에서 직선관계를 보였고, 검출한계는 25ppb였다. 상대표준편차는 0.5ppm에 대하여 ${\pm}0.72%$였고, 시료의 채취속도는 $60samples\;hr^{-1}$였다. 여러 가지 양이온과 음이온의 방해효과를 조사한 결과, NI(II), Cu(II), Fe(III) 및 $CN^-$이 많은 방해를 하였다. 그러나 운반체흐름에 $1.0{\times}10^{-3}M$ EDTA 용액을 넣음으로써 금속이온들의 방해를 감소시킬 수 있었다.

• 한국결정학회지
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• 제8권1호
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• pp.15-19
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• 1997

고온고압용 autoclave에서 $Na_2CO_3$를 광화제로 하여 청색수정 단결정을 수열성장하고, 성장온도와 코발트 함입량과의 관계를 고찰하였다. $5wt.\%$의 $Na_2CO_3$ 수열용액, $343^{\circ}C$의 성장온도, $22^{\circ}C$의 온도구배, 950기압의 조건에서 $100{\times}50{\times}35mm^3$ 크기의 청색수정을 성장하였으며, 성장속도는 0.55 mm/day였다. 가시영역에서의 흡수 스펙트럼을 측정한 결과 545, 570 및 643 nm 근처에서 흡수피크가 관찰되었다. 청색의 농도는 원료내 코발트의 농도와는 무관하며 성장온도와 밀접한 관계가 있음을 확인하였다.

• 한국재료학회지
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• 제22권10호
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• pp.545-551
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• 2012

In semiconductor manufacturing, the circuit integrity of packaged BGA devices is tested by measuring electrical resistance using test sockets. Test sockets have been reported to often fail earlier than the expected life-time due to high contact resistance. This has been attributed to the formation of Sn oxide films on the Au coating layer of the probe pins loaded on the socket. Similar to contact failure, and known as "fretting", this process widely occurs between two conductive surfaces due to the continual rupture and accumulation of oxide films. However, the failure mechanism at the probe pin differs from fretting. In this study, the microstructural processes and formation mechanisms of Sn oxide films developed on the probe pin surface were investigated. Failure analysis was conducted mainly by FIB-FESEM observations, along with EDX, AES, and XRD analyses. Soft and fresh Sn was found to be transferred repeatedly from the solder bump to the Au surface of the probe pins; it was then instantly oxidized to SnO. The $SnO_2$ phase is a more stable natural oxide, but SnO has been proved to grow on Sn thin film at low temperature (< $150^{\circ}C$). Further oxidation to $SnO_2$ is thought to be limited to 30%. The SnO film grew layer by layer up to 571 nm after testing of 50,500 cycles (1 nm/100 cycle). This resulted in the increase of contact resistance and thus of signal delay between the probe pin and the solder bump.

• 한국세라믹학회지
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• 제52권6호
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• pp.514-520
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• 2015

$KY_{1-x}(WO_4)_2:Ho^{3+}/Yb^{3+}$ yellow phosphors with doping concentrations of $Ho^{3+}$ and $Yb^{3+}$ ($x=Ho^{3+}+Yb^{3+}$, $Ho^{3+}=0.05$, 0.1, 0.2 and $Yb^{3+}=0.2$, 0.45) were successfully prepared using the microwave-modified sol-gel method; their upconversion (UC) photoluminescence properties were investigated in detail. Well-crystallized particles, formed after heat-treatment at $900^{\circ}C$ for 16 h, showed a fine and homogeneous morphology with particle sizes of $2-5{\mu}m$. Under excitation at 980 nm, the UC $KY_{0.7}(WO_4)_2:Ho_{0.1}Yb_{0.2}$ and $KY_{0.5}(WO_4)_2Ho_{0.05}Yb_{0.45}$ particles exhibited excellent yellow emissions based on a strong 545-nm emission band in the green region and a very strong 655-nm emission band in the red region. Pump power dependence and Commission Internationale de L'Eclairage chromaticity of the UC emission intensity were evaluated. The spectroscopic properties were examined comparatively using Raman spectroscopy.

• 한국전기전자재료학회논문지
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• 제14권7호
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• pp.539-545
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• 2001

Undoped and Co$^{2+}$ $\alpha$-Ga$_2$S$_3$ thin films were grown by spray pyrolysis method. It has been found that these thin films have a monoclinic structure and direct optical energy gap and indirect were located to 3.477eV and 3.123 eV at 10K respectively. In the photoluminescence due to a D0A(donor-acceptor) pair recombination were observed at 502 nm and 671 nm for the $\alpha$-Ga$_2$S$_3$ thin film, where is excited by the 325 nm-line of He-Cd laser. These peaks are identified to be corresponding to the electron transition between the energy levels of Co$^{2+}$ ion sited a the T$_{d}$ symmetry point in the $\alpha$-Ga$_2$S$_3$;Co$^{2+}$ thin film. film.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제40회 동계학술대회 초록집
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• pp.107-107
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• 2011

오늘 날 transparent conductive oxide는 다양한 분야에서 활용되고 있다. 최근에는 태양전지 분야에서도 많이 활용되고 있으며, 초기에는 transmittance 및 낮은 sheet resistance 특성을 가지는 ITO가 많이 활용되었지만 thin film solar cell와 같이 hydrogenation 공정에 약한 ITO보다는 Al-doped ZnO가 사용되기 시작하면서 많은 연구가 진행되고 있다. 본 연구에서는 thin film solar cell 및 silicon heterojunction solar cell에 적용 가능한 Al-doped ZnO에 관한 연구로써 a-Si:H의 Si-H bonds에 영향을 주지 않는 낮은 영역의 substrate temperature와 power로 Al-doped ZnO를 형성하고 상기 parameter에 따른 Al-doped ZnO의 특성 변화에 대해서 분석하였다. 특히 substrate temperature가 변화할수록 carrier concentration 및 sheet resistance가 많은 변화를 보였으며 이로 인하여 transmittance 특성이 온도에 따라 좋아지다가 너무 높은 온도에서는 오히려 좋지 않게 되었다. 이는 너무 높은 carrier concentration은 free carrier absorption에 의해 transmittance 특성을 오히려 좋지 않게 한다. 우리는 본 연구를 통해 92.677% (450 nm), 90.309% (545 nm), 94.333% (800 nm)의 transmittance를 얻을 수 있었다.