유리 기판에서 RF 마그네트론 스퍼터링법으로 증착한 비정질 투명전극 스트론튬 루세네이트 박막 두께에 따른 광학 및 전기적 특성

방효진(Hyo Jin Bang),김현민(Hyun Min Kim),이종훈(Jong Hoon Lee),안지훈(Ji-Hoon Ahn),김홍승(Hong Seung Kim) 한국물리학회 2022 새물리 Vol.72 No.10

스트론튬 루세네이트 (SrRuO₃)의 전극은 페로브스케이트 구조 유전체의 유전 특성을 향상시킬 수 있어 DRAM(Dynamic Random-Access Memory) 에 가장 적합한 전극 재료로 사용되고 있다. 이러한 장점들을 가지고 있는 스트론튬 루세네이트 (SrRuO₃) 박막이 투명 전극(Transparent Conductive Oxide; TCO) 으로의 사용 가능성을 확인해 보기 위해 연구하였다. 본 연구에서, 스트론튬 루세네이트(SrRuO₃) 박막을 유리 기판 위에 RF 마그네트론 스퍼터링 법으로 상온에서 증착 하였다. 박막의 두께에 따른 광학적 특성과 전기적 특성을 관찰하기 위하여 증착 시간을 5분과 50분으로 설정하여 실험을 진행하였다. 증착 시간이 증가할수록 박막 두께가 5nm에서 68nm로 증가하였고 광 투과율이 80%에서 40%로 감소하였다. 전기적 특성인 비저항은 박막 두께가 증가 하면서 1.99 mΩ·cm 에서 26.3 mΩ·cm 로 증가하였다. 결과적으로, 스트론튬 루세네이트(SrRuO₃) 박막을 유리 기판 위에 5분 증착 하였을 때, 약 80%이상의 투과율과 4.57eV의 밴드 갭, 그리고 1.99 mΩ·cm의 비저항을 보여주었다. The SrRuO₃ electrode can improve the dielectric properties of the perovskite structure. Thus, it is the most suitable electrode material for Dynamic Random-Access Memory (DRAM). This study was conducted to investigate the possibility of the SrRuO₃ thin film as a transparent conductive oxide (TCO). In this study, an SrRuO₃ thin film was deposited on the glass substrates by the RF magnetron sputtering method at room temperature. To observe the difference in optical and electrical properties as per the thin film thickness, the deposition times were set to 5 and 50 min. As the deposition time increased, the film thickness increased from 5 to 68 nm, the optical transmittance decreased from 80% to 40%, and the resistivity (an electrical property) increased from 1.99 to 26.3 mΩ·cm. Consequently, when the SrRuO₃ thin films were deposited on the glass substrates for 5 min, a transmittance of about 80% or more, a band gap of 4.57 eV, and a resistivity of 1.99 mΩ·cm were observed, thus verifying that an SrRuO₃ electrode can improve the dielectric properties of perovskite.

F-Doped SnO₂ Thin Film/Ag Nanowire 이중층의 전기적 및 광학적 특성

김종민,구본율,안효진,이태근,Kim, Jong-Min,Koo, Bon-Ryul,Ahn, Hyo-Jin,Lee, Tae-Kun 한국재료학회 2015 한국재료학회지 Vol.25 No.3

Fluorine-doped $SnO_2$ (FTO) thin film/Ag nanowire (NW) double layers were fabricated by means of spin coating and ultrasonic spray pyrolysis. To investigate the optimum thickness of the FTO thin films when used as protection layer for Ag NWs, the deposition time of the ultrasonic spray pyrolysis process was varied at 0, 1, 3, 5, or 10 min. The structural, chemical, morphological, electrical, and optical properties of the double layers were examined using X-ray diffraction, X-ray photoelectron spectroscopy, field-emission scanning electron microscopy, transmission electron microscopy, the Hall effect measurement system, and UV-Vis spectrophotometry. Although pure Ag NWs formed isolated droplet-shaped Ag particles at an annealing temperature of $300^{\circ}C$, Ag NWs covered by FTO thin films maintained their high-aspect-ratio morphology. As the deposition time of the FTO thin films increased, the electrical and optical properties of the double layers degraded gradually. Therefore, the double layer fabricated with FTO thin films deposited for 1 min exhibited superb sheet resistance (${\sim}14.9{\Omega}/{\Box}$), high optical transmittance (~88.6 %), the best FOM (${\sim}19.9{\times}10^{-3}{\Omega}^{-1}$), and excellent thermal stability at an annealing temperature of $300^{\circ}C$ owing to the good morphology maintenance of the Ag NWs covered by FTO thin films.

Analysis and Design of Resonant Inverter for Reactive Gas Generator Considering Characteristics of Plasma Load

Hyo Min Ahn,Won-Yong Sung,Byoung Kuk Lee 대한전기학회 2018 Journal of Electrical Engineering & Technology Vol.13 No.1

This paper analyzes a resonant inverter to generate plasma. The resonant inverter consists of a full bridge converter, resonant network and reactor to generate a magnetic field for plasma generation. A plasma load has very distinct characteristics compared to conventional loads. The characteristics of plasma load are analyzed through experimental results. This paper presents the study on the resonant network, which was performed in order to determine how to achieve a constant current gain. Another important contribution of this study is the analysis of drop-out phenomenon observed in plasma loads which is responsible for unpredictable shutdown of the plasma generator that requires stable operation. In addition, the design process for the resonant network of a plasma generator is proposed. The validity of this study is verified through simulations and experimental results.

Analysis and Design of LCL Filter with Passive Damping Circuits for Three-Phase Grid-Connected Inverters

Hyo-Min Ahn,Chang-Yeol Oh,Won-Yong Sung,Jung-Hoon Ahn,Byoung-Kuk Lee 전력전자학회 2015 ICPE(ISPE)논문집 Vol.2015 No.6

In this paper, a design method of LCL and a generalized model with various types of passive damping circuits for the three-phase grid-connected inverter are proposed. Based on the generalized model, theoretical analysis is carried out to examine the performance of the designed LCL filter. The validity of the proposed filter model is verified by simulation and experimental results.

Drosophila Torsin Proteins in Regulation of Motor-controls and Oxidative Stress

Hyo-Min Ahn,Jong-Bok Seo,Young Ho Koh 한국응용곤충학회 2014 한국응용곤충학회 학술대회논문집 Vol.2014 No.04

Early onset torsion dystonia is caused by mutations in DYT1 gene in humans. Two deletion mutations and one missense mutation were found from patients with this devastating disorder. The molecular and cellular etiology underlying this disorder is not still understood yet. Because vertebrates have more than 4 homologs in their genomes, it is very hard to elucidate the exact in vivo functions of Torsin1A. Instead, Drosophila has only one homolog named Torsin. To investigate the in vivo functions of Torsin, we generated and characterized transgenic flies expressing coding regions of Torsin mRNA or double stranded inhibitory DNA constructs (RNAi). The specific antibodies for Drosophila Torsin (DTor) also were generated. The transgenic expression of DTor cDNA or RNAi in all tissue induced significant changes in DTor proteins levels. Even though expression of DTor cDNA in neuronal system increased the amount of DTor proteins, expression of DTor RNAi did not significantly altered the amount of DTor. Consistent with this result, the numbers of flies with motor-activity were not discernible among neuronal expression lines. However, flies expressing DTor cDNA or RNAi on muscles showed significantly altered locomotor ability, suggesting that DTor plays important roles in regulating motor-activity at the post-synaptic terminals of motor neurons. In addition, DTor over-expressing flies showed increased resistance to H2O2. In the future study, we will found how those phenotypes were accomplished by performing various experiments. (NRF-2012R1A1A4A01011674: HRF-S-201.-6)

Drosophila Torsin proteins in regulation of motor-controls and oxidative stress

Hyo-min Ahn,Jong Bok Seo,Young Ho Koh 한국응용곤충학회 2013 한국응용곤충학회 학술대회논문집 Vol.2013 No.10

Early onset torsion dystonia is caused by mutations in DYT1 gene in humans. The molecular and cellular etiology underlying this disorder is not still understood yet. Because vertebrates have more than 4 homologs in their genomes, it is very hard to elucidate the exact in vivo functions of Torsin1A. Instead, Drosophila has only one homolog named Torsin. To investigate the in vivo functions of Torsin, we generated and characterized transgenic flies expressing coding regions of Drosophial Torsin (DTor) cDNA or double stranded inhibitory DNA constructs (RNAi). The transgenic expression of DTor cDNA or RNAi in all tissue induced significant changes in DTor proteins levels as well as ability of motor controls. In addition, DTor over-expressing flies showed increased resistance to H2O2 or paraquat. In the future study, we will found how those phenotypes were accomplished by performing various experiments.

Regeneration and genetic transformation by Agrobacterium tumefaciens in Brassica napus

Hyo-Min Ahn(안효민),Hyun-Jeong Oh(오현정),Kwan-Jeong Song(송관정) 한국원예학회 2004 한국원예학회 학술발표요지 Vol.2004 No.5

Analysis and Design of Resonant Inverter for Reactive Gas Generator Considering Characteristics of Plasma Load

Ahn, Hyo Min,Sung, Won-Yong,Lee, Byoung Kuk The Korean Institute of Electrical Engineers 2018 Journal of Electrical Engineering & Technology Vol.13 No.1

This paper analyzes a resonant inverter to generate plasma. The resonant inverter consists of a full bridge converter, resonant network and reactor to generate a magnetic field for plasma generation. A plasma load has very distinct characteristics compared to conventional loads. The characteristics of plasma load are analyzed through experimental results. This paper presents the study on the resonant network, which was performed in order to determine how to achieve a constant current gain. Another important contribution of this study is the analysis of drop-out phenomenon observed in plasma loads which is responsible for unpredictable shutdown of the plasma generator that requires stable operation. In addition, the design process for the resonant network of a plasma generator is proposed. The validity of this study is verified through simulations and experimental results.

Analysis and Design of LCL Filter with Passive Damping Circuits for Three-phase Grid-connected Inverters

Hyo Min Ahn,Chang-Yeol Oh,Won-Yong Sung,Jung-Hoon Ahn,Byoung Kuk Lee 대한전기학회 2017 Journal of Electrical Engineering & Technology Vol.12 No.1

The analysis and design process of the LCL filter with passive damping circuits for threephase grid-connected inverter are presented based on the generalized model of LCL filter. Several types of the passive damping circuits in previous studies could be compared and analyzed by using the generalized model considering various design criteria of passive damping circuits. According to the analysis in this paper, a reasonable configuration of passive damping circuits for three-phase gridconnected inverters is proposed. The validity of the proposed design process is verified by informative simulation and experimental results.

Agrobacterium-Mediated Transformation of Rape (Brassica napus) with Phytoene Synthase

Hyo Min Ahn,Hyun Jeong Oh,Gyeong Lyong Jeon,Se Yong Lee,Kwan Jeong Song 한국원예학회 2006 Horticulture, Environment, and Biotechnology Vol.47 No.3

An Agrobacterium-mediated transformation of rape (Brassica napus) was established. Regeneration condition was determined at 0.1 ㎎ㆍL?¹ α-naphthaleneacetic acid (NAA) and 1.0 ㎎ㆍL?¹ 6-benzylamino purine (BA) from evaluating the regeneration response of hypocotyl explants on MS medium supplemented with various levels of NAA and BA. Hypocotyl explants were excised from in vitro germinated 7-day-old seedlings and infected with A. tumefaciens LBA4404 harboring the binary vector pBIci-psy(+) carrying the nptII gene and the phytoene synthase (PSY) gene cloned from citrus. After co-cultivation for 2 days at 24 ± 1℃ in the dark, the explants were transferred to selective regeneration medium consisting of MS basal medium with 0.1 ㎎ㆍL?¹ NAA, 1.0 ㎎ㆍL?¹ BA, 50 ㎎ㆍL?¹ kanamycin, and 500 ㎎ㆍL?¹ carbenicillin, and incubated at 24 ± 1℃ under 16 h photoperiod of 30 μ㏖ㆍm?²ㆍs?¹ for 4 weeks. The regenerated shoots were transferred to shoot elongation and rooting medium consisting of MS basal medium with 0.1 ㎎ㆍL?¹ gibberellic acid and 0.3% activated charcoal. Putative transgenic plants were potted and acclimatized in a plastic greenhouse. To confirm gene transfer and transgene expression, polymerase chain reaction (PCR), Southern blot, and reverse transcription-PCR analysis were performed for putative transgenic plants. Several transgenic rapes with one to three copies of PSY gene were produced, but the side effects including leaf bleaching, rolling, and dwarfness were observed in some cases.