• 반도체디스플레이기술학회지
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• 제10권1호
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• pp.23-26
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• 2011

New organic light-emitting diodes with structure of ITO/DNTPD/TAPC/$Bebq_2/Bebq_2$:RP-411/ET-137/LiF/Al using the selective doping of 5% RP-411 in a single $Bebq_2$ host in the two wavelength(green, red) emitter formation were proposed and characterized. In the experiments, with a 300${\AA}$-thick undoped emitter of $Bebq_2$, three kinds of devices with different thicknesses of 30${\AA}$, 40${\AA}$ and 50${\AA}$ in the doped emitter of $Bebq_2$:RP-411 were fabricated. The electroluminescent spectra showed two peak emissions at the same wavelengths of 511 nm and 622 nm for the fabricated devices. When the device with a 30${\AA}$-thick doped emitter is referred as "D-1", the device with a 40${\AA}$-thick doped emitter is referred as "D-2" and the device with a 50${\AA}$-thick doped emitter is referred as "D-3", the relative intensity of 622 nm to 511 nm at two wavelength peaks was higher in the D-2 and the D-3 than in the D-1. The devices of D-1, D-2 and D-3 showed the color coordinates of (0.43, 0.46), (0.46, 0.44) and (0.48, 0.43) on the CIE chart, respectively.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.1220-1221
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• 2008

Submicron-sized conical-type tungsten(W) field-emitters based on carbon nanotubes(CNTs) are fabricated with the configuration of CNTs/catalyst(Ni)/buffer(Al/Ni/TiN)/W-tip. This study focuses on elucidating how the Al/Ni/TiN stacked buffer layer affects the structural properties of CNTs and the electron-emission characteristics of CNT-emitters. Field-emission scanning electron microscopy(FESEM), high-resolution transmission electron microscopy(HRTEM), and x-ray photoelectron spectroscopy(XPS) are used to monitor the nanostructures, surface morphologies, chemical bonds of all the catalysts and CNTs grown. The crystalline structure of CNTs is also characterized by Raman spectroscopy. Furthermore, the measurement of field-emission characteristics for the field-emitters fabricated shows that the emitter using the Al/Ni/TiN stacked buffer reveals the excellent performances.

• 한국진공학회지
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• 제12권4호
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• pp.218-227
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• 2003

AlGaAs/GaAs HBT 에미터 오믹 접촉을 위해 n형 InGaAs에 대한 Pd/Si/Ti/Pt 및 Pd/Si/Pd/Ti/Au 오믹 접촉 특성을 조사하였다. Pd/Si/Ti/Pt 오믹 접촉의 경우, 증착 상태에서는 접촉 비저항을 측정할 수 없을 정도의 비오믹 특성을 보였으며, $375^{\circ}C$에서 10초 동안 열처리한 경우 $5\times10^{-3}\Omega\textrm{cm}^2$의 높은 접촉 비저항을 나타내었다. 그러나 열처리 조건을 $425^{\circ}C$, 10초로 변화시킬 경우 $2\times10^{-6}\Omega\textrm{cm}^2$의 낮은 접촉 비저항을 나타내었다. Pd/Si/Pd/Ti/Au 오믹 접촉의 경우, $450^{\circ}C$까지의 열처리 동안에 전반적으로 우수한 오믹 특성을 나타내어 $400^{\circ}C$, 20초의 급속 열처리 조건에서 최저 $3.9\times10^{-7}\Omega\textrm{cm}^2$의 접촉 비저항을 나타내었다. 두 오믹 접촉 모두 오믹 재료와 InGaAs의 평활한 계면을 유지하면서 우수한 오믹 특성을 나타내어, 화합물 반도체 소자의 오믹 접촉으로 충분히 응용 가능하였다. Pd/Si/Ti/Pt 및 Pd/Si/Pd/Ti/Au를 AlGaAs/GaAs HBT의 에미터 오믹 접촉으로 사용하여 제작된 HBT 소자의 고주파 특성을 측정한 결과, 차단 주파수가 각각 63.9 ㎓ 및 74.4 ㎓로, 또한 최대공진 주파수가 각각 50.1 ㎓ 및 52.5 ㎓로 우수한 작동특성을 보였다.

• 한국재료학회지
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• 제21권4호
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• pp.212-215
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• 2011

New organic light-emitting diodes with structure of indium-tin-oxide[ITO]/N,N'-diphenyl-N, N'-bis-[4-(phenyl-m-tolvlamino)-phenyl]-biphenyl-4,4'-diamine[DNTPD]/1,1-bis-(di-4-poly-aminophenyl) cyclohexane[TAPC]/bis(10-hydroxy-benzo(h)quinolinato)beryllium[Bebq2]/Bebq2:iridium(III)bis(2-phenylquinoline-N,C2')acetylacetonate[(pq)2Ir(acac)]/ET-137[electron transport material from SFC Co]/LiF/Al using the selective doping of 5%-(pq)2Ir(acac) in a single Bebq2 host in the two wavelength (green, orange) emitter formation were proposed and characterized. In the experiments, with a 300${\AA}$-thick undoped emitter of Bebq2, two kinds of devices with the doped emitter thicknesses of 20${\AA}$ and 40${\AA}$ in the Bebq2:(pq)2Ir(acac) were fabricated. The device with a 20${\AA}$-thick doped emitter is referred to as "D-1" and the device with a 4${\AA}$-thick doped emitter is referred to as "D-2". Under an applied voltage of 9V, the luminance of D-1 and D-2 were 7780 $cd/m^2$ and 6620 $cd/m^2$, respectively. The electroluminescent spectrum of each fabricated device showed peak emissions at the same two wavelengths: 508 nm and 596 nm. However, the relative intensity of 596 nm to 508 nm at those wavelengths was higher in the D-2 than in the D-1. The D-1 and D-2 devices showed maximum current efficiencies of 5.2 cd/A and 6.0 cd/A, and color coordinates of (0.31, 0.50) and (0.37, 0.48) on the Commission Internationale de I'Eclairage[CIE] chart, respectively.

• Transactions on Electrical and Electronic Materials
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• 제11권6호
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• pp.249-252
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• 2010

The ground amorphous powder was consolidated into a dense sintered body with a typical ultrafine $Al_2O_3-GdAlO_3$ eutectic structure by spark plasma sintering (SPS). Sintered material with ultrafine and dense eutectic structure was obtained by an appropriate combination of rapid quenching and SPS at lower temperature and more quickly than by conventional sintering. The $Al_2O_3$-based rare earth eutectic ceramics for solar cell emitters are believed to have a higher efficiency and the $Al_2O_3$ based eutectic ceramics with ultrafine grains will be one of the promising materials showing excellent selective emitter characteristics.

• Journal of Information Display
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• 제2권3호
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• pp.78-85
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• 2001

The growth of carbon nanotubes(CNTs) in anodic aluminum oxide(AAO) template and their application to a field emitter are described. AAO templates were fabricated by anodizing bulk aluminum and sputtered thin Al film on Nb-coated Si wafers. After Co catalyst had been electrochemically deposited into the bottom of the pores in AAO template, CNTs were grown by pyrolyzing $C_2H_2$. Depending on the reaction conditions, CNTs grew up to or over the top of the pores in AAO template with different structures. The morphology and structure of CNTs were observed with a scanning electron microscope and a transmission electron microscope. The diameter of CNTs strongly depended on the size of the pores in AAO template and the growing conditions. The electron field emission measurement of the samples resulted in the turn-on field of 1.9-2.2 $V/{\mu}m$ and the field enhancement factor of 2450-5200. The observation of high field enhancement factors is explained in terms of low field screening effect.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1996년도 춘계학술발표회논문집(4)
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• pp.101-106
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• 1996

For the application of the neutron flux mapping, an accurate calculation of the sensitivity is required because the sensitivity is proportional to the neutron flux density. Sensitivity is defined as the current per unit length per unit neutron flux and it mainly depends on the depression factor(f), the escape probability from the emitter($\varepsilon$1) and the charge build-up factor of the insulator layer(c). A Monte Carlo simulation was accomplished to calculate the sensitivity of rhodium emitter material and alumina(Al$_2$O$_3$) insulator with a cylindrical geometry, based on the (n,${\beta}$) interaction and on other interaction including the secondary electron generation for the more accurate estimation of the sensitivity. From the simulation results, factors fur the sensitivity were accurately calculated and compared with other theoretical and experimental values. In addition, the sensitivity linearly increases and saturates as the emitter radius increases. The accomplished method is useful in the analysis for the change of SPND sensitivity as a function of burn-up and in the optimum design of SPND.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 Techno-Fair 및 추계학술대회 논문집 전기물성,응용부문
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• pp.90-91
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• 2007

Nano-sized conical-type tungsten(W) field-emitters based on carbon nanotubes(CNTs) are fabricated with the configuration of CNTs/catalyst/buffer/W-tip by adopting various buffer layers, such as TiN, Al, Al/TiN, and Al/hi/TiN. This study focuses on elucidating how the buffer layers affect the structural properties of CNTs and the electron-emission characteristics of CNT-emitters. Field-emission scanning electron microscopy(FESEM) and high-resolution transmission electron microscopy(HRTEM) are used to monitor the nanostructures and surface morphologies of all the catalysts and CNTs grown. The crystalline structure of CNTs is also characterized by Raman spectroscopy. Furthermore, the measurement of field-emission characteristics for all the field-emitters fabricated shows that the emitter using the Al/Ni/TiN stacked buffer reveals the most excellent performances, such as maximum emission current of $202{\mu}A$, threshold field of 2.08V/${\mu}m$, and long-term (up to 24h) stability of emission current.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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• pp.603-603
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• 2012

최근에 전면 emitter의 doping profile이 다른 selective emitter solar cell은 실제 제작시단파장 영역에서 많은 gain을 얻을 수 없어 LBC 구조의 태양전지에 관한 연구가 많이 진행되고 있다. 본 연구는 TCAD simulation을 이용하여 후면에 형성되는 locally doped BSF(p++) region의 doping profile의 변화에 따른 태양전지 특성에 관한 연구이다. Al으로 형성되는 local back contact의 doping depth 및 surface concentration에 따른 전기적, 광학적 분석을 통해 주도적인 인자를 분석하고 최적화하였다. 특히 doping depth에 따른 변화보다는 surface concentration의 변화에 따른 특성변화가 주도적으로 나타났다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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• pp.687-687
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• 2013

In rearpoint contact solar cell and the PERC (passivated emitter rear contact) type cell, surfaces were passivated by SiO2 or Al2O3 to increase solar cell efficiency. Therefore, we have investigated the effect of surface passivation for crystalline silicon solarcell using mass-production atomic layer deposited (ALD) Al2O3. The patttern which consists of cylinders with 100um diameter and 5um height was formed by PR patterning on Si (100) substrate and then Al2O3 of about 10nm and 20nm thickness was deposited by ALD. The pattern in 10 nm Al2O3 film was removed by dipping in aceton solution for about 10 min but the pattern in 20 nm Al2O3 film was not. The influences of process temperature and heat treatment were investigated using microwave photoconductance decay (PCD) and Quasi-Steady-State photoconductance (QSSPC). The solar cell process used in this work combines the advantage of using the applicability of a selective deposition associated with a ALD passivation and the use of low-cost screen print for the contacts formation.