A Comparative Study of Nanoparticle-Ink-Based CIGSSe Thin Film Solar Cells on Different Back Contact Substrates

Se Jin Park,Jin Woo Cho,Gi Soon Park,Jae Seung Jeong,김지현,고두현,황윤정,민병권 대한화학회 2016 Bulletin of the Korean Chemical Society Vol.37 No.3

The effect of the back contact electrode in nanoparticle-ink-based CIGSSe solar cells was investigated using different glass substrates with either a fluorine-doped SnO2 (FTO) conducting layer or a molybdenum (Mo) conducting layer. The morphologies, crystal structures, and compositional distributions of the Cu(In x Ga1– x )(S y Se1– y )2(CIGSSe) films are very similar in spite of the different back contact materials. The observed performances of the solar cell device, however, are somewhat different. The device that was fabricated on the FTO back contact substrate revealed a lower open-circuit voltage ( V oc) and fill factor (FF) than the Mo back contact substrate, resulting in lower solar cell efficiencies (6.5% for FTO and 7.4% for Mo). The differences between the behaviors are attributed to the interfacial properties between the CIGSSe film and the back contact electrode.

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>

체간안정화 훈련이 만성 뇌졸중 환자의 호흡기능에 미치는 효과

이경진(Kyeong-Jin Lee),정주현(Ju-Hyeoun Jeong),조명래(Myeong-Rae Jo),김세윤(Se-Yoon Kim),김난수(Nan-Soo Kim) 대한심장호흡물리치료학회 2019 대한심장호흡물리치료학회지 Vol.7 No.1

Purpose : The purpose of this study is to examine the effects of trunk stability training on improving trunk control, respiratory function, and respiratory muscle activation in stroke patients. Methods : The subjects were assigned to two groups: the intervention group (n=15) and the control group (n=15). Both groups participated in a conventional stroke rehabilitation program, but the intervention group also received trunk stability training for 30 minutes a day, 3 times a week, for 6 weeks. The main trunk stability exercise consisted of the dead bug exercise. Trunk control was assessed using a trunk impairment scale, and respiratory function (pulmonary function and respiratory muscle function) was assessed using spirometry. The data were analyzed using the Pearson correlation, independent t-test, and paired t-test. Results : Trunk control was significantly positively correlated with pulmonary function and respiratory muscle strength. Both groups showed a significant increase in trunk control and respiratory function. Conclusion : This study demonstrated that a conventional stroke rehabilitation program and trunk stability training have positive effects on respiratory function and respiratory muscle activation in stroke patients.

포화수증기압 개념에 대한 예비 과학 교사들의 이해

정진우,박세진,김윤지 韓國敎員大學校 敎育硏究院 2009 敎員敎育 Vol.25 No.4

본 연구는 예비과학교사들이 포화수증기압 개념을 설명하는 과정에서 나타나는 이해를 밝히고자 하였다. 과학교육을 전공하는 여섯 명의 예비과학교사들을 대상으로 포화수증기압에 대한 설명을 요구하는 반구조화된 면담이 이루어졌다. 전사된 면담 내용과 비디오자료, 그리고 설명 과정에서 그려진 스케치 자료를 분석하여 참여자의 이해를 구조화하였다. 연구 결과, 예비과학교사가 대기 중의 물 개념을 설명하는 과정에서 다양한 이해가 표출되었다. 포화수증기압에 대한 이해로 분자운동론적 설명, 대기의 영향을 고려한 분자운동론적 설명, 기화압력을 이용한 설명, 확산 개념을 이용한 설명, 수증기의 공간을 한정시키는 설명이 나타났다. 예비과학교사들은 포화수증기압 개념에 대해 다양한 대안 개념을 가지고 있으며, 물의 상태 변화에 대한 분자운동론적 이해와 포화수증기압 개념을 통한 이해가 서로 연결되지 못하고 있음을 보여주었다. The purpose of this study is to analyze the understandings that represent that, in this course, the preservice science teachers have explained the concept of saturation vapor pressure. To do so, semi-structured interviews that requested students to explain saturation vapor pressure to six preservice science teachers were carried out. The preservice science teachers' understanding of the material was constructed by analyzing transcribed protocols, video tapes, and sketches that were drawn during the explanation. As a result of the research, a variety of understandings was discovered when the preservice science teachers explained the concept of atmospheric water. Understandings about saturation vapor pressure include the idea of molecular motion; the molecular motion model is considered to influence atmospheric pressure, the evaporation pressure model, the diffusion model and the limited space model. Preservice science teachers had alternative conceptions of saturation vapor pressure. The understanding of saturation vapor pressure and the understanding of the molecular motion model describing the change of water state are not connected.

이성분 양이온성 계면활성제 혼합용액의 임계미셀농도에 대한 연구 1. CTAB와 다른 양이온성 계면활성제 CTB 및 DTAB 혼합용액

김진형,오세웅,고정수 木浦大學校基礎科學硏究所 1999 基礎科學硏究誌 Vol.17 No.-

The critical micelle concentration (??) in a micellar state of the mixed surfactant systems of cetyltrimethylammonium bromide (CTAB) with cetylpyridinium bromide(CPB) and dodecyltrimethylammonium bromide (DTAB) were determined at 25℃ as a function of the overall mole fraction of CTAB by the use of surface tension method. CMC values of pure CTAB, CPB, and DTAB were 9.95×10-4 M, ?? M, and ?? M, respectively. Interaction parameterβ value of CPB-CTAB mixture was evaluated as -1.3. In case of DTAB-CTAB mixture, constancy in β value was not obtained over all composition of the mixture.

전치부 반대교합아동의 발음장애에 관한 음향적 연구

박정삼,손동수,이상훈,김진태,한세현,장기택,김종철 大韓小兒齒科學會 1996 大韓小兒齒科學會誌 Vol.23 No.2

It has widely known for speech problem in patients with malocclusion,but there have been insufficient studies on degrees of serverity.Patients with openbite and CIⅢ malocclusion usually have speech problem.It has widly known that fricative /s/ is pronunciated most abnomally in CIⅢ malocclusion than any other consonant.Therefore 20 childen with anterior crossbite selected for control group.7 sounds such as /사(sa),서(sδ),소(so),수(su),스(sω),시(si),세(se)/ were recorded,and the formants and formants ratio were measured by using Sensimetric Speech Station,which is speech analyzing program in IBM pc. The results were as follows: 1.In anterior crossbite group,F1 of all 7 sounds were significantly higher than normal anterior relationship group(P<0.05). 2.There were no significant difference in F2 between two groups except/소(so),수(su)/(P>0.05). 3.In anterior crossbite group,F2/F1 ratio of all 7 sounds were significantly smaller than normal anterior relationship group(P<0.05). 4.There were no significant difference in accordance with tongue position(P>0.05).

토양으로부터 항세균성 물질을 생산하는 Streptomyces sp. 의 분리

오현정,정완석,김세재,김창진,고영환 제주대학교 생명과학연구소 1999 제주생명과학연구 Vol.2 No.-

제주도의 토양에서 분리된 방선균 307주를 대상으로, paper disc법과 시험관 희석 배양법을 사용하여 항세균성 물질을 생산하는 균주를 선별하였다. 약 3.3%에 상당하는 분리주들이 Escherichia coli 8749, Staphylococcus aureus 6538 그리고 Pseudomonas solanacearum 10692에 대해 항균효과를 나타냈고, 그 중에서 가장 높은 항균활성을 나타내는 BL93 균주를 최종선별하여 동정하였다. BL93 균주의 배양학적, 형태학적, 생리학적, 생화학적 그리고 화학분류학적 특성을 기준으로 볼 때 Streptomyces violaceus와 유사하였기에, Streptomyces sp. BL93으로 명명하였다. 이 균주가 생산하는 항세균성 물질은 butanol보다도 물에 더 잘 녹는 극성화합물로 chloroform이나 ethylacetate에는 거의 용해되지 않았다. 100℃에서 30분간 가열 처리해도 활성의 소실이 거의 없었고, pH 3∼9범위에서 안정하였다. 분리균주 BL93은 aspartocin을 생산하는 Streptomyces violaceus와 유사함으로, BL93이 생산하는 항세균성 물질의 동정 및 aspartocin과의 비교 검토가 선행되어야 할 것이다. Three hundred and seven isolates of Actinomycetes were isolated and purified from soil samples in Cheju Is. to screen antibacterial compounds. About 3.3% of the isolates showed antibacterial activity, and one of them, BL93, showed relatively higher antibacterial activity against Escherichia coli 8749, Staphylococcus aureus 6538 and Pseudomonas solanacearum 10692 by both paper disc method and tube dilution incubation method. The isolate BL93 was similar to Streptomyces violaceus based upon its cultural, morphological, physiological, biochemical and chemotaxanomic characteristics. It was designated as Streptomyces sp. BL93. The antibacterial substance produced by the isolate BL93 had higher affinity for water than butanol and was insoluble in chloroform or ethylacetate. Most of its antibacterial activity was retained even after heating at 100℃ for 30min and was stable at pH ranges 3 to 9. As the isolate BL93 was tentatively identified to be Streptomyces violaceus, the antibacterial substance preferentially need to be identified and compared with aspartocin, an antimicrobial compound produced by Streptomyces violaceus.

銳敏化된 304 스텐레스鋼의 水素脆性에 관한 硏究

金貞錫,金辰漢,朴世潤 부산대학교 공과대학 1987 硏究報告 Vol.33 No.-

This paper discusses the hydrogen embrittlement observed when static load tests were run on sensitized type 304 stainless steel specimens. The specimens were cathodically charged with hydrogen at room temperature in a in solution of H₂SO₄to which was added 100mg of sodium arsenite (As₂O₃) per liter using a platinum anode at various current densities. When hydrogen is introduced into the Cr depleted zone, the austenitic lattice is expanded, are it causes the dislocation and stacking fault density and induce partial transformation of the austenite to the martensitic phases α(bcc) and ε(hcp). The increase in hydrogen cracking susceptibility by sensitizing is attributed to deformation induced martensite. The fracture mode was changed from intergranular to transgranular by cold working and sensitizing.

산업부산물인 Fly Ash의 라이닝콘크리트에의 적용에 관한 실험적 연구

최세진,임정열,정우성,김완영,김무한 공주대학교 자원재활용신소재지역협력센터 2000 2차년도 센터 사업 성과집 Vol.2000 No.1

This is an experimental study to analyze the usability of fly ash in the tunnel lining concrete. For this purpose, the mix proportion of plain concrete and concrete using fly ash(the replacement of 15 and 30% by weight of cement) to satisfy slump 15cm, air content 5% and compressive strength 270kgf/cm2, was selected. And then tests for slump, setting time, compressive strength, tensile strength, drying shrinkage and adiabatic temperature rise were performed. According to test results, it was found that the concrete using fly ash 15% (FA 15 concrete) was better than the plain concrete and FA 30 concrete. FA 15 concrete was more useful than the others in reducing the drying shrinkage : the drying shrinkage strains of FA 15 concrete after 20 weeks of air drying was lower about 10% than the plain concrete, and lower 6% than FA 30 concrete. And the highest compressive strength after curing for 28 days of 365kgf/cm2 was obtained from FA 15 concrete. This was almost 10-20% improvement in compressive sterngth, compare to the plain concrete and FA 30 concrete. And the effect of 5~7.5℃ of concrete using fly ash for hydration heat reducing was calculated. Therefore, concrete using fly ash 15% (FA 15) was expected to improve the performance of lining concrete.

Mathcad를 사용한 혼합계면활성제의 상호작용 파라미터의 계산

김수진,고정수,오세웅 木浦大學校 基礎科學硏究所 2001 基礎科學硏究誌 Vol.19 No.-

Home-built program was developed for the calculation of the interaction parameters for the mixed surfactant systems using a commercial software, Mathcad. The program was applied to the mixed surfactant systems which were published already, and gave the same values as the previous results. The program might be able to show the best averaged interaction parameters for the mixtures of surfactants through the process iteratively.