진공 석영관에서 Selenization한 CuInSe₂ 박막 특성분석

양현훈(Yang, Hyeon-Hun),백수웅(Back, Su-Ung),김한울(Kim, Han-Wool),한창준(Han, Chang-Jun),나길주(Na, Kil-Ju),김영준(Kim, Young Jun),소순열(So, Soon-Youl),박계춘(Park, Gye-Choon),이진(Lee, Jin),정해덕(Chung, Hae-Deok) 한국신재생에너지학회 2010 한국신재생에너지학회 학술대회논문집 Vol.2010 No.06

본 실험에서는 CuInSe₂ 3원물질을 화학량론적 조성비가 되도록 박막을 제조하기 위해 각 단위원소를 원자비에 맞춰 전자선가열 진공증착기를 사용하여 Cu, In, Se 순으로 증착하였다. 90?C이하의 온도에서 CuIn₂, In상이 주를 이루며, 100?C이상에서는 Cu_{11}In_9상이 나타나기 시작하고 In상이 증가하였다. 10^{-3}torr이상의 진공석영관에서 열처리와 동시에 Selenization을 통해 제작된 CuInSe₂박막은 열처리온도 250?C에서는 CuxSe, CuSe등의 2차상들이 나타나다가 450?C이상의 고온에서 CuInSe₂ 단일상을 형성하였다. 이로부터 진공중에서 반응을 시켰을 때, 더 낮은 온도에서 반응이 일어나고 열역학적으로 보다 안정한 소수의 화합물들이 쉽게 형성됨을 확인할 수 있었다. 특히 250?C에서는 Sphalerite 구조를 가지다가 350?C이상의 온도에서 Selenization하였을 때 Chalcopyrite 구조를 가졌다. 박막이 두꺼워지면서 결정립의 크기가 커지고 응력이 작아지는 특성을 보였다. 에너지 밴드갭은(E_g)은 Cu/In 성분비율이 클수록 작은값을 보였으며, 결절립크기가 증대되므로 결국 흡수계수가 낮아짐을 알 수 있다. 또한 두께가 증가할수록 전반적으로 흡수계수가 증가하였고 Cu/In의 성분비율이 0.97일 때 기초흡수파장은 1,169nm이고 에너지밴드갭은 1.06eV이었으며, 두께 1.5{mu}m이상일 때 전반적으로 양호한 상태의 p-type CuInSe₂박막을 제작하였다.

A Study on Properites of PV Solar cell n-type ZnS Using RF Sputtering Method

양현훈(Yang, Hyeon-Hun),김한울(Kim, Han-Wool),한창준(Han, Chang-Jun),소순열(So, Soon-Youl),박계춘(Park, Gye-Choon),이진(Lee, Jin),정해덕(Chung, Hea-Deok),이석호(Lee, Suk-Ho),백수웅(Back, Su-Ung),나길주(Na, Kil-Ju),정운조(Jeong, Woon 한국신재생에너지학회 2011 한국신재생에너지학회 학술대회논문집 Vol.2011 No.05

ZnS thin films were deposited with the radio frequency magnetron sputtering technique at various temperatures and sputtering powers. With the increase in the deposition temperature and the decrease in the radio frequency sputtering power, the crystallinity was increased and the surface roughness was decreased, which lead to the decrease in the electrical resistivity of the film. It is also clearly observed that, the intensity of the (111) XRD peak increases with increasing the substrate temperature. On the other hand, as seen in the FWHM decreased with increasing the substrate temperature. Since the FWHM of the (111) diffraction peak is inversely properties to the grain size of the film, then grain size of ZnS thin film increases with increasing the substrate temperature. The electrical resistivity and optical transmittance of the ZnS film as a function of the post-annealing temperature. It can be seen that with the annealing temperature set at 400?C, the resistivity decreases to a minimum value of 2.1{times}10^{-3};{Omega}cm and the transmittance increases to a maximum value of 80% of the ZnS film.

A Study on Properites of PV Solar cell AZO thin films post-annealing by RTP technique

양현훈(Yang, Hyeon-Hun),김한울(Kim, Han-Wool),한창준(Han, Chang-Jun),소순열(So, Soon-Youl),박계춘(Park, Gye-Choon),이진(Lee, Jin),정해덕(Chung, Hea-Deok),이석호(Lee, Suk-Ho),백수웅(Back, Su-Ung),나길주(Na, Kil-Ju),정운조(Jeong, Woon 한국신재생에너지학회 2011 한국신재생에너지학회 학술대회논문집 Vol.2011 No.05

In this paper, ZnO:Al thin films with c-axis preferred orientation were prepared on Soda lime glass substrates by RF magnetron sputtering technique. AZO thin film were prepared in order to clarify optimum conditions for growth of the thin film depending upon process, and then by changing a number of deposition conditions and substrate temperature conditions variously, structural and electrical characteristics were measured. For the manufacture of the AZO were vapor-deposited in the named order. It is well-known that post-annealing is an important method to improve crystal quality. For the annealing process, the dislocation nd other defects arise in the material and adsorption/decomposition occurs. The XRD patterns of the AZO films deposited with grey theory prediction design, annealed in a vacuum ambient(2.0{times}10-3Torr)at temperatures of 200, 300, 400 and 500?C for a period of 30min. The diffraction patterns of all the films show the AZO films had a hexagonal wurtzite structure with a preferential orientation along the c-axis perpendicular to the substrate surface. As can be seen, the (002)peak intensities of the AZO films became more intense and sharper when the annealing temperature increased. On the other hand, When the annealing temperature was 500?C the peak intensity decreased. The surface morphologies and surface toughness of films were examined by atomic force microscopy(AFM, XE-100, PSIA). Electrical resistivity, Gall mobility and carrier concentration were measured by Hall effect measuring system (HL5500PC, Accent optical Technology, USA). The optical absorption spectra of films in the ultraviolet-visibleinfrared( UV-Vis-IR) region were recorder by the UV spectrophotometer(U-3501, Hitachi, Japan). The resistivity, carrier concentration, and Hall mobility of ZnS deposited on glass substrate as a function of post-annealing.

Overexpression of a high-affinity phosphate rtansporte gene from tobacco (NtPT1) enhances phosphate uptake and accumulation in transgenic rice plants

Myoung Ryoul Park,So Hyeon Back,G. Benildo,De Los Reyes,Song Joong Yun 한국육종학회 2007 한국육종학회 학술발표회 발표요지 Vol.39 No.1

시뮬레이션 수업을 받은 간호대학생의 공감능력과 의사소통능력이 문제해결능력에 미치는 영향

김혜옥(Hae-Ok Kim),소현진(Hyeon-Jin So),정세윤(Se-Yun Jeong),변성욱(Seong-Uk Byeon),백민지(Min-Ji Back),박준우(Jun-Woo Park) 한국콘텐츠학회 2021 한국콘텐츠학회논문지 Vol.21 No.12

본 연구의 목적은 시뮬레이션 수업을 받은 간호대학생의 공감능력과 의사소통능력이 문제해결능력에 미치는 효과를 파악하기 위함이다. 대상자는 시뮬레이션 수업 경험자 3, 4학년으로 234명이다. 자료수집은 2021년 4월 26일부터 5월 10일까지이다. 자료 분석은 SPSS/WIN version 25.0 프로그램으로 기술통계, 차이 검정은 Independent t-test, One way ANOVA, Pearson’s correlation coefficient, Multiple regression으로 하였다. 연구결과 공감능력은 7점 만점에 5.29점, 의사소통능력은 5점 만점에 3.30점, 문제해결능력은 5점 만점에 3.51점이다. 공감능력과 의사소통능력은 문제해결능력에 양의 상관관계였다. 문제해결능력에 영향을 미치는 요인은 공감능력, 의사소통능력 및 교내실습기간 순이였다. 이에 대한 설명력은 64.6%였다. 결론적으로 시뮬레이션 수업을 받은 간호대학생의 문제해결능력을 향상시키기 위해서는 지속적인 시뮬레이션 수업을 통하여 공감능력 및 의사소통능력을 증진시키기 위한 전략이 필요하다. The purpose of this study was to investigate the effects of empathy and communication skills on nursing problem-solving skills of nursing students who received simulation classes. The subjects of this study were composed of 234 students in the 3rd and 4th grades who already took simulation classes. The data was collected from April 26th to May 10th, 2021. The data was analyzed with the SPSS WIN 25.0 program. Descriptive statistics and mean differences were analyzed using an independent t-test, one-way ANOVA, Pearson’s correlation coefficient, and multiple regression. As a result, the average points of empathy skills were 5.29 out of 7, communication skills were 3.30 out of 5, and problem-solving skills were 3.51 out of 5. Empathy skills and communication skills were positively correlated with problem-solving skills. The predicting factors on problem-solving skills were empathy and communication skills, on-campus practice period, and gender in order. The explanatory power of these factors was 64.6%. In conclusion, in order to improve the problem-solving ability of nursing students, a strategy is needed to enhance empathy and communication skills through continuous simulation classes.

Thermoelectric Properties and Chemical Potential Tuning by K- and Se-Coalloying in (Pb0.5Sn0.5)1-xKxTe0.95Se0.05

Dianta Ginting,Chan-Chieh Lin,Gareoung Kim,Song Yi Back,Bora Won,조현용,Jae Hyun Yun,Hyeon Seob So,Hosun Lee,Byung-Kyu Yu,Sung-Jin Kim,Jong-Soo Rhyee 대한금속·재료학회 2019 ELECTRONIC MATERIALS LETTERS Vol.15 No.3

Topological crystal insulator (TCI) and topological Dirac semimetals have topologically nontrivial surface and bulk state,respectively. The parent compound of Pb 0.5 Sn 0.5 Te exhibiting TCI band inversion has particle-hole symmetry owing to thegapless Dirac band implying a strong electron–hole bipolar compensation in Seebeck coeffi cient. We recently reported thatweak perturbation of TCI state can enhance thermoelectric performance signifi cantly due to highly dispersive and degeneratedenergy bands. It is a great interest that the further increase of chemical potential has benefi ciary to thermoelectric performancein the vicinity of topological phase transition. Here we investigate the thermoelectric properties of the co-doping eff ect by Kand Se in (Pb 0.5 Sn 0.5 ) 1− x K x Te 0.95 Se 0.05 ( x = 0.0, 0.005, 0.010, 0.015, 0.02) compounds. K-doping increases the band gap from0.15 eV (Pb 0.5 Sn 0.5 Te) to 0.21 eV ( x = 0.05) as well as increasing chemical potential resulting in the suppression of bipolardiff usion eff ect. In spite of the suppression of bipolar diff usion eff ect by K-doping, the power factor in K-doped compoundis decreased signifi cantly than the one of non-doped Pb 0.5 Sn 0.5 Te 0.95 Se 0.05 compound. It indicates that when we increasechemical potential further on the breaking of topological band inversion, the thermoelectric performance is deterioratedbecause the chemical potential resides far from the linear band dispersions which become conventional material. The ZTfor the K-doped (Pb 0.5 Sn 0.5 ) 1− x K x Te 0.95 Se 0.05 is obtained as 0.91 at 750 K for x = 0.017 which is increased as much as 99%comparing to the pristine compound Pb 0.5 Sn 0.5 Te but it is reduced value (51.5%) comparing to those of Pb 0.5 Sn 0.5 Te 0.95 Se 0.05compound. We believe that this research is valuable on the confi rmation that the weak perturbation of topological state andappropriate chemical potential tuning are important criteria in high thermoelectric performance.