PEDOT:PSS/GaN 하이브리드 접합 소자의 PEDOT:PSS 두께에 따른 I-V 특성

신민정,안형수,이삼녕 한국물리학회 2014 새물리 Vol.64 No.11

We fabricated a hybrid structure composed of an organic semiconductor poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) and an inorganic semiconductor GaN. PEDOT:PSS films with various thicknesses were deposited on to an n-GaN epilayer by using a spin coater, and the dependence of the current-voltage characteristics on the thickness of the PEDOT:PSS layer was examined. The PEDOT:PSS layer was homogeneously deposited on GaN epilayer, moreover the thickness of PEDOT:PSS layer was decreased by increasing the spin speed. An optimum device characteristic with the highest current-rectifying behavior was observed when the thickness of the PEDOT:PSS layer was about 125 nm. The relatively-high ideality factor (n $\sim$ 14) seemed to be associated with carrier tunneling or recombination at the hybrid interface due to the presence of various defects. 본 연구에서는 유기물 반도체인 PEDOT:PSS와 무기물 반도체인 GaN를 이용하여 하이브리드 구조를 제작하였다. 스핀 코팅 방법을 이용해 GaN 위에 다양한 두께를 가지는 PEDOT:PSS층을 제작하였고 PEDOT:PSS층의 두께에 의존하는 전류-전압 특성을 연구하였다. 단면 측정을 통해, PEDOT:PSS 층이 GaN 에피층 위에 빈틈없이 균일하게 증착되었을 뿐만 아니라, 코팅 속도가 증가함에 따라 두께가 점차적으로 감소함을 확인할 수 있었다. 또한 PEDOT:PSS가 약 125 nm의 두께 일 때 가장 좋은 다이오드 특성을 확인 할 수 있었고, 이때 캐리어의 터널링 및 소자 계면에 존재하는 결함들에 의해 큰 값을 가지는 이상계수 (n $\sim$ 14)를 관찰 할 수 있었다.

HVPE 방법으로 제작한 GaN 나노막대의 성장시간에 따른 특성분석

신민정,최윤정,안형수,이삼녕,하동한 한국물리학회 2010 새물리 Vol.60 No.4

We studied the growth time dependence of GaN nanorods grown by hydride vapor phase epi-taxy(HVPE). The growth temperature were 645℃ and the gas flow rate of HCl:NH₃ was 1:40. Each of experiments was done for 10, 20, 40, 60, and 120 min. The morphologies and crystal stru-ctures of GaN nanorods were analyzed by field emission scanning electron microscopy(FE-SEM) and X-ray diffraction(XRD) for each GaN layers. Nucleation process was started at first stage and then GaN nanorods were grown on the basic layer of bulk type, eventually, they combined together with time procedure. The CL spectra recorded at room temperature reveal the band-edge emission at 374-385nm and a broad luminescence at 610-630nm. There appeared a red shift of the CL band-edge peaks with increasing sample depth. This behavior was explained by internal absorption effect. Hydride vapor phase epitaxy 방법을 이용하여 GaN 나노막대를 645℃의 온도에서 HCl과 NH₃의 유량비율을 1:40으로 하여 성장하였다. 성장시간이 10분, 20분, 40분, 60분, 그리고 120분으로 증가함에 따른 GaN 나노막대의 성장 메커니즘을 알아보기 위해 전계 방출 주사전자현미경(FE-SEM)을 이용하여 시편의 표면과 단면을 관찰하였으며, X-선 회절을 이용하여 구조적 특성을 분석하였다. 나노막대는 초기의 핵화 과정으로부터 시작하여 점차 로드 형태로 변하였으며 시간이 더욱 경과함에 따라 로드들이 서로 병합하였다. 상온에서의 cathodoluminescence 스펙트럼에서는 374-385 nm에서의 band-edge(BE) emission과 610-630 nm에서의 결함에 의한 넓은 luminescence를 보였다. BEemission 피크는 전자 빔 에너지가 증가함에 따라 적색 이동하는 경향을 보였다.

Investigation of Nanomorphology Change in Bulk Heterojunction Films using Synchrotron X-ray Diffraction

신민정,김화정,이문호,김영규,허규용 한국물리학회 2010 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.56 No.61

Here we report the in-situ measurement of the nanomorphology (nanostructure) change in blend films of poly(3-hexylthiophene) (P3HT) and 1-(3-methoxycarbonyl)-propyl-1-phenyl-(6,6)C61(PCBM), which is one of the standard bulk heterojunction combinations for organic solar cells. The time-dependent variation of the nanostructures at a fixed temperature was monitored with a grazing angle incident X-ray diffraction system empowered by a synchrotron radiation source. In order to understand the influence of film thickness, we fabricated blend films with two different thicknesses (75 nm and 270 nm) using the same substrates coated with a hole-collecting buffer layer as used for the corresponding solar cells. Results uncovered that the nanomorphology was not monotonically changed but fluctuated up to 30 min, followed by stabilization in the presence of continuous small variations upon further annealing. This fluctuation was similarly observed for both 75 nm and 270nm thick blend films, even though the thicker films exhibited slightly delayed behavior to reach a well-defined alignment of the P3HT chains.

Optimized performance and limiting factors in organic solar cells with polymer : fullerene blend films

신민정,김화정,이인혁,김영규 한국고분자학회 2008 한국고분자학회 학술대회 연구논문 초록집 Vol.33 No.2

담임교사의 관심도에 대한 지각이 자아개념에 미치는 영향

신민정,반상진 한국지역사회교육상담학회 2002 지역사회교육상담연구 Vol.1 No.1

니켈-크롬 합금에 폭로된 치과기공사들에서 자매염색분체 교환 빈도

신민정,성재혁,김웅철,이세훈 가톨릭대학산업의학센타 산업의학연구소 2002 韓國의 産業醫學 Vol.41 No.2

Nonprecious metal alloys were used in dental laboratories, may contain nickel, chromium, cobalt, molybdenum, beryllium, and small amounts gallium, ruthenium, or aluminum. Nonprecious metal alloys tend to rapid increase in use due to the economical merit. Despite the widespread use of Nickel-Chromium alloys, claims for safety of these alloys have not yet been accepted universally. This study was performed to investigate cytogenetic toxicity of Nickel-Chromium alloy in human cultured lymphocytes by sister chromatid exchange(SCE) which is a sensitive indicator of carcinogen and mutagen. Total subjects was divided into the two groups, including 34 Nickel-Chromium alloy exposed dental technicians and 24 control group members. 1. The frequencies of SCE were high in older than 40 years, but these was no statistical significance in two groups. 2. The effect of smoking on SCE values as higher than non-smokers in two groups, but there was no statistical significance. 3. The work duration also affected SCE frequencies, but these values didn't show any statistical difference between two groups. 4. The significant difference of SCE frequencies was found between Nickel-Chromium alloy exposed group and control group. 5. The SCE frequencies of current smoking exposed group was the highest and that of non-smoking control group was the lowest. The present study has shown that occupational exposure to Nickel-Chromium alloy is associated with an increase in SCE frequency.

반응표면분석법을 이용한 Nitinol 형상기억합금의 마이크로 전해연마의 가공특성에 관한 연구

신민정,이은상 한국공작기계학회 2006 한국공작기계학회 추계학술대회논문집 Vol.2006 No.-

A nearly equatomic nickel-titanium alloy(Ni-Ti alloy, Nitinol) is a metal alloy composed of Ni and Ti around 50% respectively in that it possesses a so-called shape memory. Nitinol can be put use for various applications which need purity and high precision surface of product using surface treatment methods. So, ectropolishing is adopted to final polishing of nitinol. Electropolishing has been used in metal alloy, but its essential details and electropolishing mechanism for nitinol have not been reported yet as a demand. So, the aim of this study is to investigate the characteristic of electropolishing nitinol in terms of current density, polishing time, electrode gap. And the optimum experimental condition about each parameters was obtained using by response surface methodology.

성남시 호화 청사 건립 사례로 살펴본 예산 낭비

신민정 이화여자대학교 법정대학 행정학과 2010 梨花行政 Vol.- No.15

도시영구임대주택지역의 주민참여 활성화 방안 -대구광역시 달서구 통반장의 역할을 중심으로- /

신민정,채현탁 대구대학교 사회복지연구소, 2004 社會福祉硏究 Vol.25 No.-

고콜레스테롤혈증 환자에서 식사요법이 혈청 지질농도에 미치는 영향

신민정,임현숙,정남식,조승연,김성순 대한영양사협회 2001 대한영양사협회 학술지 Vol.7 No.4

High serum cholesterol level is a major risk factor for coronary heart disease(CHD). Nutrition therapy of hypocholesterolemic diets with increased physical activity is the essential step in the treatment of the hypercholesterolemic patients. The purpose of this study was to evaluate the short-term effect of intensive dietary therapy combined with regular exercise in lowering serum cholesterol level. Seventy three hypercholesterolemic outpatients(mean: 268.0±24.7㎎/dl), aged 34 to 73(mean: 56±9.8yrs), who visited cardiology OPD of Yonsei Cardiovascular Center from April through October, 1998 were studied. Anthropometric measurements, usual nutrient intake survey using semiquantitative food frequency questionnaire, and daily nutrient intake analysis were performed. The nutrition counseling for the hypocholesterolemic diet and exercise therapy was performed individually. After a 4 week intensive dietary therapy, comparisons of body weight, nutrient intakes, and blood lipid concentrations were evaluated for the hypocholesterolemic effect of intensive diet therapy. After 4 weeks of intensive diet therapy, significant reductions in percent ideal body weight(p<0.01), saturated fat intake(p<0.01), and cholesterol intake(p<0.01) were observed. There were significant reductions in serum total cholesterol and LDL-cholesterol levels after 4 weeks of therapy by 8.1%(p<0.01) and 9.7%(p<0.01), respectively. Our results showed that intensive dietary therapy was effective in reductions of serum total and LDL-cholesterol levels. The goal for this dietary modification should not be temporary but rather be permanent in eating behavior accompanied by appropriately increased physical activity.