Optimization of Controllable Factors in the Aluminum Silicon Eutectic Paste and Rear Silicon Nitride Mono-Passivation Layer of PERC Solar Cells

Park, Sungeun,Park, Hyomin,Kim, Dongseop,Yang, JungYup,Lee, Dongho,Kim, Young-Su,Kim, Hyun-Jong,Suh, Dongchul,Min, Byoung Koun,Kim, Kyung Nam,Park, Se Jin,Kim, Donghwan,Lee, Hae-Seok,Nam, Junggyu,Kang Springer-Verlag 2018 METALS AND MATERIALS International Vol.24 No.3

<P>Passivated emitter and rear contact (PERC) is a promising technology owing to high efficiency can be achieved with p-type wafer and their easily applicable to existing lines. In case of using p-type mono wafer, 0.5-1% efficiency increase is expected with PERC technologies compared to existing Al BSF solar cells, while for multi-wafer solar cells it is 0.5-0.8%. We addressed the optimization of PERC solar cells using the Al paste. The paste was prepared from the aluminum-silicon alloy with eutectic composition to avoid the formation of voids that degrade the open-circuit voltage. The glass frit of the paste was changed to improve adhesion. Scanning electron microscopy revealed voids and local back surface field between the aluminum electrode and silicon base. We confirmed the conditions on the SiNx passivation layer for achieving higher efficiency and better adhesion for long-term stability. The cell characteristics were compared across cells containing different pastes. PERC solar cells with the Al/Si eutectic paste exhibited the efficiency of 19.6%.</P>

Low-Cost Contact Formation of High-Efficiency Crystalline Silicon Solar Cells by Plating

Dongseop Kim,이수홍,김정,E. J. Lee 한국물리학회 2005 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.46 No.1

High-efficiency silicon solar cells have potential applications on mobile electronic and electrical vehicles. The fabrication processes for high-efficiency cells necessitate complicated processes and expensive materials. Ti/Pd/Ag metal contacts have only been used in limited areas in spite of their good stability and low contact resistance because of expensive materials and processes. Commercial solar cells with screen-printed contacts formed by using Ag paste suffer from a low fill factor and a high shading loss because of high contact resistance and low aspect ratio. Low-cost Ni and Cu metal contacts have been formed by using electroless plating and electroplating techniques to replace the Ti/Pd/Ag and screen-printed Ag contacts. Nickel-silicide formation at the interface between the silicon and the nickel enhances stability and reduces the contact resistance, resulting in an energy conversion efficiency of 20.2 % on a 0.5 cm FZ(Float Zone) wafer. A tapered contact structure has been applied to large-area, 6.7 × 6.7 cm2, solar cells in order to reduce power loss due to the front metal contact. The tapered metal contact is realized by electroplating and results in 45 cm2 solar cells with efficiencies of 21.4 % on 2 cm FZ wafer.

Influence of laser damage on the performance of selective emitter solar cell fabricated using laser doping process

Kim, Myungsu,Kim, Donghwan,Kim, Dongseop,Kang, Yoonmook Elsevier 2015 Solar Energy Materials and Solar Cells Vol.132 No.-

<P><B>Abstract</B></P> <P>This article investigates the impact of laser damage on the performance of a selective emitter solar cell fabricated using a laser doping process (LD). After the optimization of the laser doping process, an amorphous silicon layer with a thickness of approximately 100Å was observed on the laser-doped emitter. The amorphous laser damage decreased the power conversion efficiency due to poor contact between the Ag front electrode and the selective emitter. To effectively improve the quality of the front contacts, a solution etch-back process was applied after the laser doping step (LEB), and the series resistance of the selective emitter solar cell was restored to 0.55Ω cm<SUP>2</SUP> from around 1.0Ω cm<SUP>2</SUP>. The contact formation during the LEB process clearly improved, and it was verified by comparing the densities of the Ag crystallites after Ag electrode removal from the LEB cell and the LD cell. The improvement in the formation of the front contact resulted in the LEB selective emitter solar cell recording a maximum 19.16% of power conversion efficiency, with a standard deviation of 0.055.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The influence of laser-induced damage of laser doped selective emitter solar cell was systematically investigated. </LI> <LI> After direct laser doping process, a 10nm thick a-Si layer was formed on the selective emitter region. </LI> <LI> A-Si layer suppresses contact formation requiring epitaxial regrowth of Ag. </LI> <LI> A solution etch back process effectively removed the laser induced a-Si damage and improved the cell efficiency. </LI> </UL> </P>

자기효능감과 성과의 관계에 대한 재연구

이동섭(Dongseop Lee)/김기태(Kitae Kim)/조봉순(Bongsoon Cho) 한국인사조직학회 2008 인사조직연구 Vol.16 No.4

본 연구는 과업성과의 예측변수로서의 자기효능감과 개인성격 변수들의 상대적 효과를 검증한다. 사회인지이론(social cognitive theory)은 성과를 비롯한 다양한 행위 변수를 설명하는 요인으로서 자기효능감의 중요성을 강조하였으며, 지난 30년간 많은 연구의 결과가 이를 지지하였다. 하지만 최근 Judge, Jackson, Shaw, Scott, & Rich(2007)는 메타분석결과에 의거한 경로분석을 통해, 개인성격 변수가 포함될 경우 자기효능감의 효과는 사라진다는 주장을 전개하였다. 본 논문은 Judge et al.의 연구에 내재된 방법론적인 한계를 감안할 때, 자기효능감의 과잉변수화 주장에 대해서는 보다 신중한 해석이 필요하다는 점을 지적하고, 그 대안으로 자기효능감과 Big 5 성격 변수를 동시에 포함하는 개별연구(primary study)를 통해 고유한 자기효능감 효과의 존재 유무를 살펴보았다. 156명의 대학생을 표본으로 하여 2회에 걸쳐 실시된 본 연구의 자료 분석결과에 의하면, Judge et al.(2007)에서와는 달리, 성격 변수의 효과는 통계적으로 유의하지 않은 반면, 자기효능감은 과업성과에 대해 일관적으로 유의한 예측력을 보였다. The purpose of the study is to empirically examine the relative impacts of Big 5 personality factors and self efficacy on task performance, controlling for mental ability and experience. Self-efficacy, the central variable of human regulatory mechanisms in social cognitive theory, has been proposed to be one of the most powerful cognitive determinants of human behavior(Bandura, 1986, 1997, 2006a; Locke & Latham, 1990). Research for over two decades has shown that self-efficacy has an impact on a variety of motivational and behavioral outcomes in clinical, athletic sport, educational, and various organizational settings (Holden, 1991; Holden, Moncher, Schinke, & Barker, 1990; Multon, Brown, & Lent, 1991; Stajkovic & Luthans, 1998). However, Judge, Jackson, Shaw, Scott, and Rich (2007) recently called the validity of these findings into question. They suggested that the unique contribution of self-efficacy in predicting performance may become negligible if individual traits, which have been largely neglected in social cognitive theory, are considered simultaneously. Using meta-analytic path analysis on the relationships among Big 5 personality traits, mental ability, experience, self-efficacy, and task performance, they reported a substantially reduced incremental predictive validity of self-efficacy when individual difference variables were controlled for. On the basis of this finding, they concluded that given the significant relationships of personality and intelligence to self-efficacy, task-specific self-efficacy may simply be a superfluous byproduct of a smart and generally confident person (Judge et al., 2007). We argue that the conclusion made by Judge et al.(2007) is premature and potentially erroneous. In testing the incremental predictive validity of self-efficacy on performance with individual difference variables controlled for, Judge et al. combined psychometric meta-analysis and path analysis, a procedure we found has critical limitations. First, the biggest problem in the procedure Judge et al. used concerns that relative predictive power between Big 5 personality traits and self-efficacy, which is the most important aspect of their model, had not been examined by any of the individual studies included in their meta-analytic synthesis. In other words, the “relative” part of data is entirely missing, and this makes their conclusion about relative predictive power in fact based on missing data. Missing data is considered one of the most critical problems in this procedure because estimation of certain relationships (e.g., path coefficients) in the model may become difficult or distorted due to missing data (Becker & Schram, 1994; Viswesvaran & Ones, 1995). Second, due to the systematic missing data in Judge et al.(2007), it may be possible that different parts of the model (e.g., the relationships between Big 5 traits and performance, between self-efficacy and performance, and between Big 5 traits and self-efficacy) are based on substantially differing populations. This variation in meta-analytic correlations is a critical issue, for the test of a path model can be affected even when only one of the variables included in the path model is moderated by a certain other variable (Viswesvaran & Ones, 1995). A series of moderator analyses conducted by Judge et al. themselves showed that the relationship between self-efficacy and performance was stronger, for example, when self-efficacy was measured with grid type measures rather than with Likert type measures, when performance domain was relatively specifically identifiable task performance rather than overall job performance, and when performance was assessed objectively rather than subjectively. We view these results as indicating numerous sources of systematic variation in their path model. Given the scarcity of research properly evaluating the relative predictive validity of self-efficacy, more primary studies including both self-efficacy and various

Far-side 충돌 시 센터에어백 유무에 따른 인체상해 분석

김동섭(Dongseop Kim),윤영한(Younghan Youn),박지양(Jiyang Park),오명진(Myungjin Oh),정경진(Kyungjin Jung),곽영찬(Youngchan Kwak),손창기(Changki Son),신재곤(Jeakon Shin),이은덕(Eundok Lee) 한국자동차공학회 2017 한국자동차공학회 부문종합 학술대회 Vol.2017 No.5

공간 효율성 향상을 위해 로봇청소기를 활용하는 URC 공간플래너 시스템의 방향성 제안

김동섭(Kim, Dongseop) 인제대학교 디자인연구소 2013 Journal of Integrated Design Research (JIDR) Vol.12 No.2

2003년 정보통신연구진흥원이 제안한 URC (Ubiquitous Robot Companion)개념은 로봇 자체에서 처리되던 센싱, 프로세싱 및 행동 기능을 네트워크를 통해 분산하는 시스템으로서 프로세스의 과부하, 과도한 체중, 비대한 몸집의 문제에서 벗어나 공간을 효율적으로 관리할 수 있는 작고, 지능적인 협업중심의 로봇개발에 대한 가능성을 열어주었다. 이에 따라 RFID를 활용해 로봇의 위치인식 기능을 향상시킨 시스템에 대한 선행연구를 고찰함으로써 로봇청소기의 인식능력과 사물에 대한 인지능력이 3차원적으로 강화될 수 있음을 인식하고 이것이 공간을 효율적으로 관리하고 활용할 수 있도록 돕는 ‘URC 공간플래너’의 개발을 제안하였다. 기본적으로 이 시스템은 한 개의 서버프로그램(소프트웨어 로봇)과 각기 다른 기능과 역할을 가진 두 개의 하드웨어 로봇이 한 세트로 협업한다. 이때 한 대의 하드웨어 로봇은 사물을 식별하고 위치를 인식하며, 다른 하나는 정리정돈과 운반조립의 기능을 담당한다. 그리고 소프트웨어 로봇은 시스템 전반에 대한 판단과 명령의 기능을 담당한다. 먼저 이 URC 공간플래너는 공간에 있는 사물을 효율적으로 관리하는 과제를 수행한다. 가장 기본적으로 청소의 기능을 수행하며, 어질러진 사물들을 제자리로 옮기고 이동의 변화를 기록하는 업무를 담당한다. 둘째로 하나의 단일공간을 다목적 공간으로 활용하도록 사물의 배치를 변경하여 공간을 변화시킨다. 기존의 연구들이 지능형 사물들 간의 네트워크에만 치우진 반면, 이 연구는 네트워크로 연결된 세 개의 개체가 공간 내 사물의 위치를 효율적으로 변화시키고 공간의 기능을 변화시키는 시스템에 대한 제안이라는 점에서 차별화된다. The concept of URC is utilized which is proposed by Institute for Information Technology Advancement in Korea, 2003. This is a system which disperses sensing, processing and acting through the network, which not only can help the robot escape from problems of overloaded processing, overweight and huge figure, but allow the possibility of a small, intelligent, multi-bodied robot. Therefore, it is proved that, with analyzing the preceding researches of RFID system to improve the location recognition, the robot cleaner’ capabilities of 3 dimensional space recognition and object recognition could be strengthened and the advance of ‘URC Space Planner’ could be made possible. Based on this result, two suggestions are made. Basically, one software robot and two hardware robots with different functions could work together as one set to improve the efficiency of space. For this, the software robot takes function of judgment and command, one hardware robot recognizes the detailed information of objects and 3 dimensional space, and the other hardware robot take function of the arrangement in order and the transportation and assembly. Frist of all, this URC space planing system manages the objects in a space. It not only works as a simple vacuum cleaner, but also picks up and move the objects to their original places and records all the changes of their moves. Second, expanding the functions further, it has been proposed to utilize a small-scale space as a multipurpose space to heighten the functionality. Previous researches have focused on networking of intelligent objects, but this paper attempts to propose of a new corporative URC system in which three individual tools work together to change the functions of a space by moving and relocating objects.

Scaling up issues for 1.6x0.9 m2 large area application of Cu(In,Ga) (Se,S)₂ solar module

Mijoung KIM,Dongho LEE,Dongseop KIM,Yoonmook KANG,Junggyu NAM,Yongjei LEE,Jungyup YANG 한국진공학회 2016 한국진공학회 학술발표회초록집 Vol.2016 No.8

국내 태양광 발전 기술/사업 동향 및 현안

김동섭(Dongseop Kim),남정규(Junggyu Nam),최용우(Yongwoo Choi) 한국신재생에너지학회 2016 한국신재생에너지학회 학술대회논문집 Vol.2016 No.11

[special issue: 디지털 아키텍처] 가상 공간디자인의 현재와 미래

김동섭(Kim Dongseop) 대한건축학회 2004 建築 Vol.48 No.11

플라스틱 유래 타르 제거를 위한 니켈 촉매 합성 전략

최동섭(Dongseop Choi),김지율(Jiyull Kim),김나연(Nayeon Kim),이현경(Hyeon Kyeong Lee ),이경우(Gyoung Woo Lee ),장세진(Se Jin Jang),주지봉(Ji Bong Joo) 유기성자원학회 2019 유기성자원학회 학술발표대회논문집 Vol.2019 No.춘계

1950 년대 이후 플라스틱 산업이 크게 성장하면서, 기존재료의 대체재로서 이용이 높아 그 사용범위와 사용량은 지속적으로 확대되어 왔다. 이로 인해, 플라스틱 폐기물로 발생량도 지속적으로 증가하는 추세이다. 최근 소각 처리에 대한 문제점으로 인하여, 폐플라스틱의 처리에 대한 관심이 매우높아지고 있다. 가스화 공정은 고온에서 이론적 산소량보다 적은 산화제(산속 혹은 스팀)를 공급하여수소를 포함하는 합성가스를 생산하는 방법이다. 폐플라스틱을 가스화 연료로 사용할 경우, 버려지는폐기물로 부터 합성가스를 생산할 수 있어 그 경제적 이익 매우 크다. 하지만 가스화공정에서 발생하는 타르 성분은 점도가 높고 비점이 높은 유기화합물로 이를 제거하지 않으면 공정 운전에 무리를주게 되어 전체 설비 가동에 문제가 생긴다. 본 발표에서는 가스화공정에서 발생되는 타르를 경제적이고 효 과적으로 제거하기 위한 타르 제거 촉매를 제조하는 전략에 대해서 발표하고자 한다. 타르제거 촉매반응에서 가장 문제가 되는 코킹 문제와 열적 소결 현상을 방지하기 위해 여러 가지 조촉매도입 및 코어-쉘 구조의 촉매를 제조하고자 한다.