Cu(In,Ga)Se₂ 나노입자을 이용한 광흡수층 치밀화에 따른 Se 분위기의 열처리 효과

윤경훈(Yoon, Kyung-Hoon),김기현(Kim, Ki-Hyun),안세진(Ahn, Se-Jin),안병태(Ahn, Byung-Tae) 한국신재생에너지학회 2006 한국신재생에너지학회 학술대회논문집 Vol.2006 No.06

나노입자를 이용하여 치밀한 Cu(In,Ga)Se₂ 태양전지용 광흡수층을 제조하기 위해 먼저, 콜로이달 방법으로 합성된 20nm이하의 CIGS 나노입자를 저가의 스프레이 법을 이용하여 CIGS 막을 제조하였다. 제조된 CIGS막을 two-zone RTP (rapid temperature Process) 방법으로 Se 분위기 안에서 열처리를 행하였다. 입자의 치밀화를 위해 기판의 온도, Se 증발온도와 수송가스의 유량을 조절하여 CIGS 입자성장을 행하였다. 그러나, Se의 증발온도가 높을수록 CIGS와 MO 박막 사이에서 MoSe₂ 층이 형성되었다. 형성된 MoSe₂층의 부피 팽창으로 인해 하부의 유리기판과 Mo층 사이에서 peeling off 현상이 발생했다. 이러한 Peeling off현상을 억제하면서 CIGS 나노입자 성장을 하기 위해, Se 공급을 빨리 할 수 있도록 Se의 증기압을 높였으며, 최적조건에서 급속 열처리 공정을 통해 CIGS 나노입자 성장과 치밀화를 위한 소결거동을 관찰하였다.

Chalcogenization-Derived Band Gap Grading in Solution-Processed CuIn_<i>x</i>Ga_1–<i>x</i>(Se,S)₂ Thin-Film Solar Cells

Park, Se Jin,Jeon, Hyo Sang,Cho, Jin Woo,Hwang, Yun Jeong,Park, Kyung Su,Shim, Hyeong Seop,Song, Jae Kyu,Cho, Yunae,Kim, Dong-Wook,Kim, Jihyun,Min, Byoung Koun American Chemical Society 2015 ACS APPLIED MATERIALS & INTERFACES Vol.7 No.49

<P>Significant enhancement of solution-processed CuInxGa1-x(Se,S)(2) (CIGSSe) thin-film solar cell performance was achieved by inducing a band gap gradient in the film thickness, which was triggered by the chalcogenization process. Specifically, after the preparation of an amorphous mixed oxide film of Cu, In, and Ga by a simple paste coating method chalcogenization under Se vapor, along with the flow of dilute H2S gas, resulted in the formation of CIGSSe films with graded composition distribution: S-rich top, In- and Se-rich middle, and Ga- and S-rich bottom. This uneven compositional distribution was confirmed to lead to a band gap gradient in the film, which may also be responsible for enhancement in the open circuit voltage and reduction in photocurrent loss, thus increasing the overall efficiency. The highest power conversion efficiency of 11.7% was achieved with J(sc) of 28.3 mA/cm(2), V-oc of 601 mV, and FF of 68.6%.</P>

Physical & Chemical Deposition Techniques for Cu(In,Ga)Se2-Based Thin Film Solar Cells (초)

( Kyung Hoon Yoon ),( Jae Ho Yun ),( Se Jin Ahn ),( Byung Tae Ahn ) 대한금속재료학회 ( 구 대한금속학회 ) 2007 대한금속재료학회 학술대회 개요집 Vol.2007 No.1

Ga 함유량에 따른 Cu(In_1-xGa_x)Se₂ 박막 태양전지에 관한 연구

송진섭(Song, Jin-Seob),윤재호(Yoon, Jae-Ho),안세진(Ahn, Se-Jin),윤경훈(Yoon, Kyung-Hoon) 한국신재생에너지학회 2007 한국신재생에너지학회 학술대회논문집 Vol.2007 No.06

Cu(In_1-xGa_x)Se₂(CIGS)는 매우 큰 광흡수계수를 가지고 있으므로 박막형 태양전지의 광흡수층 재료로서 많은 연구가 진행되고 있다. 박막이 태양전지의 광흡수층으로 이용되기 위해서는 큰 결정크기와 평탄한 표면, 적당한 전기적 특성을 가져야 한다. 이러한 특성들은 CIGS 박막의 조성에 큰 영향을 받고 있는 것으로 보고되고 있다. 본 연구에서는 동시증발법을 이용하여 Cu/(In+Ga) 비를 0.9로 고정한 후 Ga 조성(Ga/(In+Ga)의 비 : 0.32, 0.49, 0.69, 0.8, 1)을 변화시켜 Wide band gap CIGS 박막태양전지를 만들었다. 기판은 soda line glass를 사용하였고 뒷면 전극으로는 Mo를 스퍼터링법으로 증착하였다. 또한 버퍼층으로는 기존에 쓰이고 있는 CdS를 CBD(Chemical Bath Deposition)법으로 층착시켰으며, 윈도우층으로는 i-ZnO/n-ZnO를 스파터링 법으로 층착하였다. 그리고 앞면전극으로는 Al을 E-beam 으로 증착하였다. 분석은 XRD, SEM, QE로 분석하였다. 위 실험에서 얻은 결과로는 Ga/(In+Ga)비가 증가할수록 Cu(In,Ga)Se2 박막은 회절 peak들이 큰 회절각으로 이동하였고, 이것은 Ga 원자와 In 원자의 원자반경의 차이에서 기인된 것으로 사료된다. 또한 Ga 조성이 증가할수록 단파장 쪽으로 이동하는 것을 볼 수 있으며, Voc가 증가하다가 에너지 밴드캡이 1.62 eV 이상에서는 Voc가 감소하는 것을 볼 수 있는데 이것은 Ga 조성이 증가할수록 에너지 밴드캡이 커지면서 defect level 이 존재하기 때문인 것으로 사료된다. Ga/(In+Ga)비가 1일 때의 변환효율은 8.5 %이고, Voc : 0.74 (V), Jsc : 17.2 (mA/cm²), F.F : 66.6(%) 이다.

비진공 나노입자 코팅법을 이용한 CIGS 박막 태양전지 제조

안세진(Ahn, Se-Jin),김기현(Kim, Ki-Hyun),윤경훈(Yoon, Kyung-Hoon) 한국신재생에너지학회 2006 한국신재생에너지학회 학술대회논문집 Vol.2006 No.06

A non-vacuum process for Cu(In,Ga)Se₂ (CIGS) thin film solar cells from nanoparticle precursors was described in this work CIGS nanoparticle precursors was prepared by a low temperature colloidal route by reacting the starting materials (CuI,;InI₃,;GaI₃;and;Na₂Se) in organic solvents, by which fine CIGS nanoparticles of about 20nm in diameter were obtained. The nanoparticle precursors were mixed with organic binder material for the rheology of the mixture to be adjusted for the doctor blade method. After depositing the mixture of CIGS with binder on Mo/glass substrate, the samples were preheated on the hot plate in air to evaporate remaining solvents ud to burn the organic binder material. Subsequently, the resultant (porous) CIGS/Mo/glass simple was selenized in a two-zone Rapid Thermal Process (RTP) furnace in order to get a solar ceil applicable dense CIGS absorber layer. Complete solar cell structure was obtained by depositing. The other layers including CdS buffer layer, ZnO window layer and Al electrodes by conventional methods. The resultant solar cell showed a conversion efficiency of 0.5%.

Association between Socioeconomic Status and Altered Appearance Distress, Body Image, and Quality of Life Among Breast Cancer Patients

Chang, Oliver,Choi, Eun-Kyung,Kim, Im-Ryung,Nam, Seok-Jin,Lee, Jeong Eon,Lee, Se Kyung,Im, Young-Hyuck,Park, Yeon Hee,Cho, Juhee Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.20

Background: Breast cancer patients experience a variety of altered appearance - such as loss or disfigurement of breasts, discolored skin, and hair loss - which result in psychological distress that affect their quality of life. This study aims to evaluate the impact of socioeconomic status on the altered appearance distress, body image, and quality of life among Korean breast cancer patients. Materials and Methods: A cross-sectional survey was conducted at advocacy events held at 16 different hospitals in Korea. Subjects were eligible to participate if they were 18 years of age or older, had a histologically confirmed diagnosis of breast cancer, had no evidence of recurrence or metastasis, and had no psychological problems at the time of the survey. Employment status, marital status, education, and income were assessed for patient socioeconomic status. Altered appearance distress was measured using the NCI's cancer treatment side effects scale; body image and quality of life were measured by the EORTC QLC-C30 and BR23. Means and standard deviations of each outcome were compared by socioeconomic status and multivariate linear regression models for evaluating the association between socioeconomic status and altered appearance distress, body image, and quality of life. Results: A total of 126 breast cancer patients participated in the study; the mean age of participants was 47.7 (SD=8.4). Of the total, 83.2% were married, 85.6% received more than high school education, 35.2% were employed, and 41% had more than $3000 in monthly household income. About 46% had mastectomy, and over 30% were receiving either chemotherapy or radiation therapy at the time of the survey. With fully adjusted models, the employed patients had significantly higher altered appearance distress (1.80 vs 1.48; p<0.05) and poorer body image (36.63 vs 51.69; p<0.05) compared to the patients who were unemployed. Higher education (10.58, standard error (SE)=7.63) and family income (12.88, SE=5.08) was positively associated with better body image after adjusting for age, disease stage at diagnosis, current treatment status, and breast surgery type. Similarly, patients who were married and who had higher education had better quality of life were statistically significant in the multivariate models. Conclusions: Socioeconomic status is significantly associated with altered appearance distress, body image, and quality of life in Korean women with breast cancer. Patients who suffer from altered appearance distress or lower body image are much more likely to experience psychosocial, physical, and functional problems than women who do not, therefore health care providers should be aware of the changes and distresses that these breast cancer patients go through and provide specific information and psychosocial support to socioeconomically more vulnerable patients.

수종의 자가 접착 레진 시멘트의 물성 및 lithium disilicate ceramic과 상아질에 대한 전단결합강도 비교

신혜진,송창규,박세희,김진우,조경모 大韓齒科保存學會 2009 Restorative Dentistry & Endodontics Vol.34 No.3

본 연구의 목적은 치면 처리와 수복물 내면의 처리가 필요 없는 자가 접착 레진 시멘트의 물성 및 lithium disilicate ceramic과 상아질에 대한 전단결합강도를 측정하고 기존의 레진 시멘트와 비교하여 임상적 유용성을 알아보고자 하는 것이다. 실험군인 자가 접착 레진 시맨트로는 Rely-X Unicem, Embrace Wetbond, Maxcem, BisCem을, 대조군으로는 기존의 레진 시멘트인 Rely-X ARC, 수복용 복합레진인 Z-350을 사용하였다. 각 레진 시멘트의 물성 평가를 위하여 테플론 주형을 이용하여 시편을 제작하고 만능 시험기를 이용하여 압축강도, 간접인장강도, 굴곡강도를 측정하였다. IPS Empress 2 및 상아질 시편에 제조사의 지시대로 Rely-X ARC군과 Z-350군에만 전처리를 시행 후 각 시멘트를 접착하고 전단결합강도를 측정하였다. 실험 결과는 다음과 같았다. 1. 자가 접착 레진 시멘트인 Biscem이 가장 낮은 물리적 성질을 나타내었다 (P<0.05). 2. 자가 접착 레진 시멘트의 상아질 및 도재에 대한 전단결합강도는 기존의 레진 시멘트에 비해 유의성 있게 낮은 값을 나타내었다 (P<0.05). 이상의 결과로 볼 때 자가 접착 레진 시멘트는 기존의 레진 시멘트에 비해 물리적 성질 및 상아질과 lithium disilicate ceramic에 대한 전단결합강도가 떨어지는 것으로 사료된다. The purpose of this study was to evaluate the physical properties of different self-adhesive resin cements and their shear bond strength on dentin and lithium disilicate ceramic and compare these result with that of conventional resin cement. For this study, four self-adhesive resin cements (Rely-X Unicem, Embrace Wetbond, Mexcem, BisCem), one conventional resin cement (Rely-X ARC) and one restorative resin composite (Z-350) were used. In order to evaluate the physical properties, compressive strength, diametral tensile strength and flexural strenth were measured. To evaluate the shear bond strength on dentin, each cement was adhered to buccal dentinal surface of extracted human lower molars. Dentin bonding agent was applied after acid etching for groups of Rely-X ARC and Z-350. In order to evaluate the shear bond strength on ceramic, lithium disilicate glass ceramic (IPS Empress 2) disks were prepared. Only Rely-X ARC and Z-350 groups were pretreated with hydrofluoric acid and silane. And then each resin cement was adhered to ceramic surface in 2 mm diameter. Physical properties and shear bond strengths were measured using a universal testing machine. Results were as follows 1. BisCem showed the lowest compressive strength, diametral tensile strength and flexural strength. (P<0.05) 2. Self-adhesive resin cements showed significantly lower shear bond strength on the dentin and lithium disilicate ceramic than Rely-X ARC and Z-350 (P<0.05) In conclusion, self-adhesive resin cements represent the lower physical properties and shear bond strength than a conventional resin cement.

공간지각 능력수준에 따른 활성화 뇌 영역의 차이 : fMRI 연구 An fMRI study

손진훈,김연희,이경화,박세훈 한국뇌학회 2001 한국뇌학회지 Vol.1 No.2

본 연구는 공간지각 능력이 높거나 낮은 사람들이 공간지각 과제를 수행하는 동안 활성화되는 뇌 영역을 확인하기 위해 수행하였다. 428명의 대학생을 대상으로 집단심리실험을 수행하여, fMRI 연구를 위한 실험참여자로 30명의 오른손잡이 여대생을 선정하였다. fMRI 실험을 위한 패러다임은 block디자인으로, 한 block 내에 공간지각과제 세 문항이 포함되어 있는 네 block으로 구성되었다. fMRI imaging은 1.5T Siemens Vision Scanner로 수집되었으며, single-shot EPI 기법으로(TR/TE: 3840/40ms, flip angle: 90, FOV: 220, 64×64 matrix) 이미지를 스캔하였다. 자료분석은 SPM-99 소프트웨어를 사용하였다. 감산(subtraction)분석결과, 공간지각 능력이 우수한 집단은 양측 대상회(bilateral cingulate gyri)와 우측 상두정엽(right superior parietal lobe)에서 뇌 활성화가 더 많이 나타났고, 우측 시상(right thalamus)과 좌측 측-후두엽(left temporooccipital)은 공간지각능력이 떨어지는 집단에서 더 많이 활성화되었다. 이는 공간지각능력의 차이가 뇌의 활성화에 기인한다는 것을 나타낸다. The purpose of study was to identify brain areas that become activated while subjects performing visuospatial tasks(VST) with different performance levels. 428 college students were evaluated for VST, then 30 females were selected for fMRI study. Subjects were selected through psychometric test and were right-handed with no history of brain injury. The fMRI paradigm was designed to have 4 blocks of each task and each block has 3 items. Imaging was performed on a 1.5T Siemens Vision Scanner. Single-shot EPI fMRI scans(TR/TE 3840/40ms, flip angle 90, FOV 220, 64x64 matrix) were acquired. Imaging data were motion-corrected, coregistered, normalized, and then analyzed using SPM-99. There was greater activation in the bilateral cingulate gyri and the right superior parietal lobe for better VST performance group, whereas the right thalamus and left temporooccipital area for poor VST performance group.

대구치에서 회전식 NiTi file의 수명과 파절양상

김진우,안병두,박세희,신혜진,조경모 大韓齒科保存學會 2005 Restorative Dentistry & Endodontics Vol.30 No.3

Intracanal separation of the rotary files is a serious concern in modern endodontic practice. The objective of this study was to compare the life span and fracture patterns of three NiTi rotary files in molar teeth. Mesiobuccal roots of upper molar (n = 150) and mesial roots of lower molar (n = 150) were divided into three groups and each group was prepared with Profile, ProTaper, and K3 respectively. Every file was used until separation and/or deterioration of the cutting blade was happened, and then the number of canals to separation and/or unwinding were recorded. Radiographs and Scanning electon microscope (SEM) photographs were taken to evaluate the patterns of separation. The results were as follows: 1. There were no significant differences in numbers of canals to separation and/or unwinding among the groups. 2. Comparing between flaring files, K3 showed significant lower numbers of canals to separation and/or unwinding (p < 0.05), and there was no significant difference between shaping files 3. Separations of instruments were occurred at the midpoint of curvatures within the canals 4. In SEM observations, ductile fractures were seen in most of cases, characterized by shallow dimples. Additional researches is needed to provide a new guideline that informs the appropriate number of times to use NiTi files. 회전식 NiTi file은쉽게 파절되는 단점이 있으나 이에 대한 연구는 아직 부족하다. 본 연구에서는 회전식 NiTi file을 이용해 실제 치아에서 근관을 형성하고, 이 때 발생하는 파절 및 변형을 연구, 분석하였다. 상악 대구치의 근심협측 치근 (n = 150)과 하악 대구치의 근심치근 (n = 150)을 실험대상으로 하여 Profile, ProTaper 및 K3로 각각 근관형성 하였다. 각 file은 파절되거나 변형이 생길 때까지 계속하여 사용한 다음 그 사용횟수를 기록하였다. 파절의 양상을 관찰하기 위해 방사선 및 주사현미경 사진을 촬영하였다. 1 세 군간의 유의할만한 사용횟수의 차이는 없었다. 2. Flaring file 간의 비교에서는 K3의 사용횟수가 통계적으로 유의성 있게 적었으며 (p < 0.05), shaping file 간에는 유의할만한 차이가 없었다. 3, 회전식 NiTi file의 파절은 근관의 최대 만곡부에서 발생하였다. 4. 주사전자현미경으로 파절면을 관찰한 결과 연성파괴의 전형적인 양상인 얕은 딤플이 관찰되었다. 일반적으로 회전식 NiTi file의 평균 사용횟수는 제조회사의 사용지침보다는 길었으며, NiTi file의 수명에 대한 새로운 사용지침을 만들기 위한 부가적인 연구가 있어야 되리라 사료된다.

컴포머 충전과정에 따른 상아질 투과도의 변화

조혜진,이경하,이세준,이광원 大韓齒科保存學會 2002 Restorative Dentistry & Endodontics Vol.27 No.4

Compomer is composed of matrix and filler; matrix is made of the combination of resins and polycarboxylic molecules that are light-cured. and a filler is a glass component which is capable of ion-release. The resin content of compomers produces polymerization shrinkage which can adversely affect marginal adaptation. Pretreatment is a fundamental step which is treated with conditioner or primer in the use of these materials. Microleakage of restorative materials has been investigated mostly by dye penetration method. Dye penetration method was not quantitative and not measured repeatedly. Fluid filtration method. introduced and developed by Pashley's group, has been extensively used for 20 years for research purpose to understand the physiology of dentin, as well as the effects of various restorative treatments on dentin permeability. It permits quantitative, nondestructive measurment of microleakage in a longitudinal manner. The purpose of this study was to evaluate the change the change of dentin permeability according to the process of compomer restoration. In this study, CI Ⅴ cavities were prepared on buccal surface of thirty extracted human molars. The prepared cavities were etched by 37% phosphoric acid. The experimental teeth were randomly divided into three groups. Each group was treated with following materials; Group 1 : Prime & Bond NT/Dyract AP, Group 2: Single Bond/F2000 compomer, Group 3 : Syntac Single Component/Compoglass. The bonding agent and compomer were applied for each group following manufactures information. Dentin permeability of each group was measured at each process by fluid filtration method; Step 1 : preparation(smear layer), Step 2 : etching(smear layer removal), Step 3 : applying the bonding agent, Step 4 : filling the compomer. Dentin permeability was expressed by hydraulic conductance(㎕ min^-1cmH_2O^-1). The data were analysed statistically using One-way ANOVA and Sheffe's method. The results were as follows : 1. Dentin permeability differences between each process were significant except between step 1 and step 2(p<0.01). 2. Dentin permeability after removal of smear layer was highly increased(p<0.01). 3. In most case, decrease of dentin permeability was obtained by applying bonding agent(p<0.01). 4. Dentin permeability differences among the experimental groups were not significant(p>0.05). 5. None of compomers used in this study showed perfect seal at the interface.