• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1999년도 추계학술대회 논문집
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• pp.553-556
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• 1999

This paper presents a proper condition to achieve above 19 % conversion efficiency using PC1D simulator. Cast poly-Si wafers with resistivity of 1 $\Omega$-cm and thickness of 250 ${\mu}{\textrm}{m}$ were used as a starting material. Various efficiency influencing parameters such as rear surface recombination velocity and minority carrier diffusion length in the base region, front surface recombination velocity, junction depth and doping concentration in the Emitter layer, BSF thickness and doping concentration were investigated. Optimized cell parameters were given as rear surface recombination of 1000 cm/s, minority carrier diffusion length in the base region 200 ${\mu}{\textrm}{m}$, front surface recombination velocity 100 cnt/s, sheet resistivity of emitter layer 100 $\Omega$/$\square$, BSF thickness 5 ${\mu}{\textrm}{m}$, doping concentration 5$\times$10$^{19}$ cm$^3$ . Among the investigated variables, we learn that a diffusion length of base layer acts as a key factor to achieve conversion efficiency higher than 19 %. Further details of simulation parameters and their effects to cell characteristics are discussed in this paper.

• 센서학회지
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• 제31권1호
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• pp.31-35
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• 2022

The efficacy improvement of the light emitting diode (LED) was studied for the realization of small-size, low power consumption, and highly sensitive bio-sensor instrument. The performance of the LED with Mg delta-doping at the interface of AlGaN/GaN super-lattice in p type cladding layer was simulated. The device with Mg delta-doping showed improved current, radiative recombination rate, electroluminescence, and light output power compared to the conventional LED structure. Under the bias condition of 5 V, the improved device exhibited 20.8% increase in the light output power. This is attributed to the increment of hole concentration from stable ionization of Mg in p type cladding layer. This result is expected to be used for the miniaturization, power saving, and sensitivity improvement of the bio-sensor system.

• 한국표면공학회지
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• 제57권4호
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• pp.325-330
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• 2024

When seawater is used in electrochemical devices, issues arise such as the adsorption of chloride ions blocking the active sites for Oxygen reduction reactions (ORR) in seawater batteries, and the occurrence of Chlorine evolution reactions (ClER) in seawater electrolysis due to chloride anions (Cl^-) competing with OH^- for catalytic active sites, potentially slowing down Oxygen evolution reactions (OER). Consequently, the performance of components used in seawater battery and seawater electrolysis may deteriorate. Therefore, conventional alloys are often used by coating or plating methods to minimize corrosion, albeit at the cost of reducing electrical conductivity. This study thus designed a corrosion-resistant layer by doping carbon with Nitrogen (N) and Sulfur (S) to maintain electrical conductivity while preventing corrosion. Optimal N,S doping ratios were developed, with corrosion experiments confirming that N,S (10:90) carbon exhibited the best corrosion resistance performance.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2011년도 춘계학술발표대회
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• pp.238.2-238.2
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• 2011

Organic thin film transistors (OTFTs) have been attracting considerable attention because of their potential use in low-cost, large area, electronic devices such as flexible displays, biochemical sensors, and smart cards. In past several years, gold/pentacene has been frequently used in OTFTs because of the high mobility of pentacene and the high work function of gold. To improve the performance of the OTFTs contact area doping of pentacene with p-doping materials are well known. In this work we demonstrated selectively contact area doping of pentacene with Iodine vapor. For effective doping elevated pentacene layer under the source-drain area was deposited and exposed to Iodine vapor. We got better electrical performance for elevated pentacene structure rather than planer structure with relatively high field-effect mobility.

• 한국결정성장학회지
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• 제7권1호
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• pp.143-150
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• 1997

본 연구는 수소로 희석된 $B_2H_6$를 도판트 소스 가스로 사용하여 이온 질량 주입(ion mass doping)을 하였을 때 다결정 박막의 전기적 특성과 도판트의 활성화시 방사 손상(radiation damage)의 효과에 대하여 고찰하였다. 다결정 박막에서 보론(boron)의 SIMS 분석과 컴퓨터 시뮬레이션인 TRIM92를 비교해서 가장 주입 확률이 높은 이온의 종류는 $B_2H_x\;^+$(x=1, 2, 3‥‥) 형태의 분자 이온임을 알았다. 높은 에너지의 질량 이온 주입 결과 시간에 따라 변화하는 비정질화된 층의 분율이 다결정 박막 내에 연속적인 비정질 충으로 존재하였다. 주입 이온의 질량 분리가 일어나지 않는 이온 질량 주입법(ion mass doping technique)에 의해 비정질화는 유발된다. 손상된 시편의 중간 열처리 온도 범위에서 도판트 활성화 거동과 역 열처리(reverse annealing) 효과가 관찰되었다. 이와 같은 연구의 결과 p-채널 다결정 박막 트랜지스터의 오프 스테이트(off-state) 전류는 방사 손상(radiation damage)에 의존한다.

• 한국표면공학회지
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• 제55권6호
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• pp.368-375
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• 2022

YSZ (Yttria Stabilized Zirconia) is used as a thermal barrier coating material for gas turbines due to its low thermal conductivity and high fracture toughness. However, the operating temperature of the gas turbine is rising according to the market demand, and the problem that the coating layer of YSZ is peeled off due to the volume change due to the phase transformation at a high temperature of 1400℃ or higher is emerging. To solve this problem, various studies have been carried out to have phase stability, low thermal conductivity, and high fracture toughness in a high temperature environment of 1400℃ or higher by doping trivalent and tetravalent oxides to YSZ. In this study, the monoclinic phase formation behavior and crystallinity were comparatively analyzed according to the total doping amount of oxides by controlling the doping amounts of Sc₂O₃ and Gd₂O₃, which are trivalent oxides, and TiO₂, which are tetravalent oxides, in YSZ. Through comparative analysis of monoclinic phase formation and crystallinity, the thermal conductivity of the thermal barrier coating layer according to the amount of doping was predicted.

• JSTS:Journal of Semiconductor Technology and Science
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• 제14권3호
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• pp.274-283
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• 2014

In this paper, the epi layer of npn SOI HBT with n+ buried layer has been studied through Sentaurus process and device simulator. The doping value of the deposited epi layer has been varied for the npn HBT to achieve improved $f_tBV_{CEO}$ product (397 GHzV). As the $BV_{CEO}$ value is higher for low value of epi layer doping, higher supply voltage can be used to increase the $f_t$ value of the HBT. At 1.8 V $V_{CE}$, the $f_tBV_{CEO}$ product of HBT is 465.5 GHzV. Further, the film thickness of the epi layer of the SOI HBT has been scaled for better performance (426.8 GHzV $f_tBV_{CEO}$ product at 1.2 V $V_{CE}$). The addition of this HBT module to fully depleted SOI CMOS technology would provide better solution for realizing wireless circuits and systems for 60 GHz short range communication and 77 GHz automotive radar applications. This SOI HBT together with SOI CMOS has potential for future high performance SOI BiCMOS technology.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.1
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• pp.249-251
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• 2003

This paper discribes the analysis of the breakdown voltage characteristics of SOI LIGBT with dual epi-layer. In case of SOI LIGBT with dual epi-layer, if we used high doping concentration in epi-layer, we obtained higher breakdown voltage compared with typical device because of charge compensation effect, and we obtained low on-state resistivity characteristic in the same breakdown voltage. In this paper, we analyzed on-state and off-state characteristics of SOI LIGBT with dual epi-layer. Breakdown voltage of proposed LIGBT was shown 125V when $T_1=T_2=2.5{\mu}m$, $N_1=7{\times}10^{15}/cm^3$ and $N_2=3{\times}10^{15}/cm^3$, respectively Although we used high doping concentration and thin epi-layer thickness, breakdown voltage was increased compared with conventional devices.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.II
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• pp.1410-1412
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• 2005

We present that the electroluminescence (EL) efficiency can be improved by doping an electron transport layer (ETL) with organic materials which can make electron current increase. The electron transport layer of aluminum tris(8 -hydroxyquinoline) (Alq3) is doped with 2-(4-Biphenylyl)-5-(4-tertbutylphenyl)- 1,3,4-oxadiazole) (butyl-PBD) to enhance the electron mobility of the ETL. The higher quantum efficiency of device having ETL using Alq3 doped with butyl-PBD can be attributed to the improved electron and hole balance.

• 전자공학회논문지A
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• 제31A권7호
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• pp.76-84
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• 1994

The characteristics of 3 inch wafer scale GaAs epitaxial wafer grown by molecular beam epitaxy for LSI process application were studied. The thickness and doping uniformity are characterized and discussed. The growth temperature and growth rate were $600^{\circ}C$ by pyrometer, and 1 $\mu$m/h, respectively. It was found that thickness and doping uniformity were 3.97% and 4.74% respectively across the full 3 inch diameter GaAs epitaxial layer. Also, ungated MESFETs have been fabricated and saturation current measurement showed 4.5% uniformity on 3 inch, epitaxial layer, but uniformity of threshold voltage increase up to 9.2% after recess process for MESFET device.