• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 D
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• pp.2285-2288
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• 2002

Recently, electronic personal dosimeters based upon silicon PIN photodiode or miniature GM tube were developed and have attracted a lot of attention because of the advantages of their nature such as indication of dose rate and the cumulative dose, and facilitation of record keeping. In this paper, we have developed a high-sensitivity electronic personal dosimeter with silicon PIN photodiode. The electronic personal dosimeter is constructed with silicon PIN photodiode, preamplifier, and shaping amplifier. To show the effectiveness of electronic personal dosimeter, we conducted nuclear radiation experiments using $\gamma$-ray Ba-133, Cs-137, and Co-60. The electronic personal dosimeter have a good linearity on $\gamma$-ray energy and activity.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 하계학술대회 논문집 C
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• pp.1422-1424
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• 1994

This paper deals with piezoresistive humidity sensor using polycrystalline silicon (Poly-Si ) with membrane in sensors of semiconductor. Poly-Si piezoresistors which have no temperature dependancy are deposited on silicon wafer, membrane is formed with micromachining technology, then polyimide is formed as a hygroscopic layer. Whereas the principle of conventional humidify sensors are based on the change in electrical properties of the material, the humidity induced volume change of a polyimide layer leads to a deformation of a silicon membrane in this case. This deformation is transformed into an output voltage by Poly-Si piezoresistive. Wheatstone bridge. Fabricated piezoresistive humidity sensors showed good linearity, response time, and long term stability.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1999년도 춘계학술대회 논문집
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• pp.103-106
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• 1999

In this paper, we suggest the FED packaging technology that have 4mm thickness, using sodalime glass-to-sodalime glass electrostatic bonding. It based on conventional silicon-glass bonding. The silicon film was deposited an around the exhausting hole on FED backside panel. And then, the silicon film of panel was successfully bonded with capping(bare) glass in vacuum environment and the FED panel was vacuum-sealed. In this method, we could achieve more 153 times increased conductance and 200 times increased vacuum efficiency than conventional tube packaging method. The vacuum level in panel, by SRG test, was maintained about low 10$_{-4}$ Torr during above two months And, the light emission was observed to 0.7-inch tubeless packaged FED. Then anode current was 34 $\mu$ A. Emission stability was constantly measured for 10 days.

• Korean Chemical Engineering Research
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• 제46권1호
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• pp.37-49
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• 2008

태양전지 기판의 원료인 폴리실리콘의 공급부족은 태양광발전산업의 비약적인 발전에 있어 최대 걸림돌이 되고 있다. 태양전지 제조에 충분한 순도로 폴리실리콘을 값싸게 제조할 수 있게 하는 공정기술의 개발은 태양광발전의 가격 경쟁력과 활용범위를 크게 증가시키는 중요한 계기가 될 수 있다. 본 총설에서는 태양전지용 폴리실리콘 제조를 위해 현재 이용 가능한 기술들을 정리해보고, 최근에 주목받고 있는 유동층 석출공정기술과 관련하여 응용범위 확대를 가로막고 있는 주요 기술적 장애요인에 대하여 중점적으로 소개하고자 한다.

• 센서학회지
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• 제22권5호
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• pp.321-326
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• 2013

In this paper, the usability of a compact silicon strain gauge load cell in a weighting disdrometer for measuring the impact load of a falling raindrop is introduced for application in a multi-meteorological sensor. The silicon strain gauge load cell is based on the piezoresistive effect, which has a high linearity output from the momentum of the raindrop and the simplicity of signal processing. The weighting disdrometer shows a high sensitivity of 7.8 mV/g in static load measurement when the diaphragm thickness of the load cell is $250{\mu}m$.

• 전기학회논문지
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• 제66권2호
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• pp.354-356
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• 2017

We focused on light management technology in amorphous silicon solar cells to suppress increase in absorber thickness for improving power conversion efficiency (PCE). $MgF_2$ and $TiO_2$ anti-reflection layers were coated on both sides of Asahi VU ($glass/SnO_2:F$) substrates, which contributed to increase in PCE from 9.16% to 9.81% at absorber thickness of only 150 nm. Also, we applied very thin $MgF_2$ as a rear reflector at n-type nanocrystalline silicon oxide/Ag interface to boost photocurrent. By reinforcing rear reflection, we could find the PCE increase from 10.08% up to 10.34% based on thin absorber about 200 nm.

• Tribology and Lubricants
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• 제28권6호
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• pp.333-339
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• 2012

Typical magneto-rheological (MR) elastomers consist of silicon-based material. A number of studies have been carried out to evaluate the vibration and tribological characteristics of silicon-based MR e-lastomers. However, these elastomers have quite low strength, so they have low wear resistance. In this study, polyurethane-based MR elastomers with performances better than those of MR elastomers. Experiments have been conducted on different MR elastomers (Pu MR elastomer, Pu-Si MR elastomer, and Pu-wrapped-Si MR elastomer) and different predefined magnetic directions (Non-Direction, Vertical Direction, and Horizontal Directionality) to evaluate the friction and wear performance under a magnetic field. The results show that Pu-wrapped-Si MR elastomer with a horizontal predefined magnetic field has the best performance in terms of wear.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.422.1-422.1
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• 2016

Graphene quantum dots (GQDs), a new kind of carbon-based photo luminescent nanomaterial from chemically modified graphene oxide (CMGO) or chemically modified graphene (CMG), has attracted extensive research attention in the last few years due to its outstanding chemical, optical and electrical properties. To further extended its potential applications as optoelectronic devices, solar cells, bio and bio-sensors and so on, intensive research efforts have been devoted to the CMG. However, the CMG, a suspension of aqueous, have problematic since they are prone to agglomeration after drying a solvent. In this study, we synthesized the GQDs from graphite and deposited on silicon substrate by kinetic spray. The photo luminescent properties of deposited GQD films were analyzed and compared with initial GQDs suspension. In addition, its carbon properties were investigated with GQDs solution properties. The properties of deposited GQD films by kinetic spray were similar to that of the GQDs suspension in water. We could provide a pathway for silicon-based silicon based device applications. Finally, the well-adjusted GQD films with photo luminescence effects will show Energy-Down-Shift layer effects on silicon solar cells. The GQD layers deposited at nozzle scan speeds of 40, 30, 20, and 10 mm/s were evaluated after they were used to fabricate crystalline-silicon solar cells; the results indicate that GQDs play an important role in increasing the optical absorptivity of the cells. The short-circuit current density (Jsc) was enhanced by about 2.94 % (0.9 mA/cm2) at 30 mm/s. Compared to a reference device without a GQD energy-down-shift layer, the PCE of p-type silicon solar cells was improved by 2.7% (0.4 percentage points).

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 C
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• pp.2410-2412
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• 2005

In this study, two types of PS substrate were fabricated for sensing of chemical and biological substances. For sensing of the humidity and chemical analyzes such as $CH_3OH$ or $C_2H_5OH$, PS layers are prepared by photoelectrochemical etching of silicon wafer in aqueous hydrofluoric acid solution. To evaluate their sensitivity, we measured the resistance variation of the PS diaphragm. As the amplitude of applied voltage increases from 2 to 6Vpp at constant frequency of 5kHz, the resistance variation for humidity sensor rises from 376.3 to $784.8{\Omega}$/%RH. And the sensitivities for $CH_3OH$ and $C_2H_5OH$ were 0.068 uA/% and 0.212 uA/%, respectively. For biological sensing application, amperometric urea sensors were fabricated based on porous silicon(PS), and planar silicon(PLS) electrode substrates by the electrochemical methods. Pt thin film was sputtered on these substrates which were previously formed by electrochemical anodization. Poly (3-methylthiophene) (P3MT) were used for electron transfer matrix between urease(Urs) and the electrode phase, and Urs also was by electrochemically immobilized. Effective working area of these electrodes was determined for the first time by using $Fe(CN)_6^{3-}/Fe(CN)_6^{4-}$ redox couple in which nearly reversible cyclic voltammograms were obtained. The $i_p$ vs $v^{1/2}$ plots show that effective working electrode area of the PS-based Pt thin film electrode was 1.6 times larger than the PLS-based one and we can readily expect the enlarged surface area of PS electrode would result in increased sensitivity by ca. 1.6 times. Actually, amperometric sensitivity of the Urs/P3MT/Pt/PS electrode was ca 0.91uA/$mM{\cdot}cm^2$, and that of the Urs/P3MT/Pt/PLS electrode was ca. 0.91uA/$mM{\cdot}cm^2$ in a linear range of 1mmol/L to 100mmol/L urea concentrations

• 한국정보통신학회논문지
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• 제23권3호
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• pp.311-317
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• 2019

먼저 광학 신호를 이용한 다양한 응용 분야에서의 핵심 요소인 광학 빔 조향 성능 향상을 위하여 실리콘 기반 격자 구조의 특성을 해석하였다. 이를 기반으로 높은 방사 효율과 좁은 빔 폭을 얻기 위해서 기존의 격자 구조 방사기에 분배 브래그 반사기(Distributed Bragg Reflector, DBR)를 집적한 구조를 제안한다. 분배 브래그 반사기의 위치에 따른 방사 효율과 방사 각도의 전치 반폭을 분석하고 이를 토대로 최적화 구조를 제안한다. 제안한 격자 구조는 상보형 금속산화 반도체(complementary metal-oxide semiconductor, CMOS) 공정과 호환 가능하며, 최대 방사 효율 87.1% 및 최소 방사 각도의 반치 전폭 $4.68^{\circ}$를 가진다.