Characterization of the copper iodide hole-selective contact for silicon solar cell application

Jeon, Kiseok,Jee, Hongsub,Park, Min Joon,Lim, Sangwoo,Jeong, Chaehwan Elsevier 2018 THIN SOLID FILMS - Vol.660 No.-

<P><B>Abstract</B></P> <P>Hole-selective contacts have been extensively studied in recent years due to their low-cost by low temperature processing (<250 °C). The γ-copper (I) iodide (CuI) behaves as a p-type semiconductor with a zinc blende structure (cubic) and it has previously been studied as a hole-selective layer in organic solar cells, solid-state dye-sensitized solar cells. In this paper, CuI thin films with wide band gaps and large work functions were fabricated on n-type silicon substrates via a thermal evaporation technique. Changes to the structural, morphological and optical properties of CuI thin films based on different thicknesses (11 to 58 nm) were analyzed. X-ray diffraction patterns reveal that poly crystalline CuI thin films a have γ-phase with preferential growth in the (111) direction. Increases in the peak intensity for the (111) diffraction plane were observed in the thicker films. Generally, deposited CuI films exhibit triangular shapes with azimuthal orientation but these shapes disappeared as the film thickness was increased. Excellent electrical and optical properties were obtained at a CuI film thickness of 11 nm; measured values were 642 mV implied voltage, ~3.00 eV band gap energy, 5.68 eV work function value and 97.5% transmittance.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Copper iodide film is proposed as hole selective contact for solar cell application. </LI> <LI> γ-Phase copper iodide films are thermally evaporated. </LI> <LI> The work function value of copper iodide films is ~5.6 eV on average. </LI> <LI> The implied V<SUB>oc</SUB> decreases as copper iodide film thickness increases. </LI> </UL> </P>

Study of Passivation for Carrier-selective Contacts Si Solar Cell with Copper Iodide Hole-selective Layer

Kiseok Jeon,Minjoon Park,Hongsub Jee,Sangwoo Limm,Chaehwan Jeong 한국신재생에너지학회 2018 한국신재생에너지학회 학술대회논문집 Vol.2018 No.11

RF 마그네트론 스퍼터를 이용하여 제작한 MIZO 박막의 특성에 미치는 기판 온도의 영향

전기석(Kiseok Jeon),지홍섭(Hongsub Jee),임상우(Sangwoo Lim),정채환(Chaehwan Jeong) 한국태양광발전학회 2016 Current Photovoltaic Research Vol.4 No.4

Mg and In co-doped ZnO (MIZO) thin films with transparent conducting characteristics were successfully prepared on glass substrates by RF magnetron sputtering technique. The Influence of different substrate temperature (from RT to 400℃) on the structural, morphological, electrical, and optical properties of MIZO thin films were investigated. The MIZO thin film prepared at the substrate temperature of 350℃ showed the best electrical characteristics in terms of the carrier concentration (4.24×10<SUP>20</SUP>㎝<SUP>-3</SUP>), charge carrier mobility (5.01 ㎠V<SUP>-1</SUP>S<SUP>-1</SUP>), and a minimum resistivity (1.24×10<SUP>-4</SUP>Ω·㎝). The average transmission of MIZO thin films in the visible range was over 80% and the absorption edges of MIZO thin films were very sharp. The bandgap energy of MIZO thin films becomes wider from 3.44 eV to 3.6 eV as the substrate temperature increased from RT to 350°C. However, Band gap energy of MIZO thin film was narrow at substrate temperature of 400℃.

Fast Retransmission Scheme for Overcoming Hidden Node Problem in IEEE 802.11 Networks

Junghwi Jeon,Chulmin Kim,Kiseok Lee,Cheeha Kim 한국정보과학회 2011 Journal of Computing Science and Engineering Vol.5 No.4

To avoid collisions, IEEE 802.11 medium access control (MAC) uses predetermined inter-frame spaces and the random back-off process. However, the retransmission strategy of IEEE 802.11 MAC results in considerable time wastage. The hidden node problem is well known in wireless networks; it aggravates the consequences of time wastage for retransmission. Many collision prevention and recovery approaches have been proposed to solve the hidden node problem, but all of them have complex control overhead. In this paper, we propose a fast retransmission scheme as a recovery approach. The proposed scheme identifies collisions caused by hidden nodes and then allows retransmission without collision. Analysis and simulations show that the proposed scheme has greater throughput than request-to-send and clear-to-send (RTS/CTS) and a shorter average waiting time.

아리미드섬유-펄프/페놀 복합재 차량 구동용 기어 개발 및 진동 감쇠 성능 평가

곽기석(Kiseok Kwak),김철(Cheol Kim),전길우(Gilwoo Jeon),김상현(Sanghyeon Kim) 한국자동차공학회 2020 한국자동차공학회 학술대회 및 전시회 Vol.2020 No.11

군 교육과정 설계 방법에 관한 연구 - 육군 대위 지휘참모과정 제병협동작전 교육체계를 중심으로 -

위진우 ( Jinwoo We ),전기석 ( Kiseok Jeon ) 미래군사학회 2023 한국군사학논총 Vol.12 No.1

본 연구의 목적은 교육과정 계획단계에서의 의사결정 방법, 과목 조정 기준·절차를 개선함으로써, 「제병협동작전 교육체계」최선안을 도출하는 것이다. 먼저「제병협동작전 교육체계」의 교육효과 제고를 위해 제안된 3개의 개선방안을 AHP를 적용하여 비교해 봄으로써 최선안을 선정하였고, 다음은 델파이 기법을 적용하여 과목 조정기준을 정립하고 정립된 조정기준에 따라 현 편성과목의 적절성을 분석함으로써 조정안을 제시하였다. 연구결과는 다음과 같다. 첫째, 선행훈련 2주 및 종합훈련 4주의 방안이 최선안으로 도출되었다. 둘째, 최선안 시행을 위해서는 96시간의 추가시간이 필요한데, 대위 지휘참모과정 편성과목을 과목 조정기준에 따라 삭제·전환·축소·통합을 검토한 결과, 보병학교는 166시간, 포병학교는 174시간, 기갑학교는 119시간의 추가시간 확보가 가능하다. 본 연구에서 제시한 연구방법과 개선방안은 군에서 교육과정을 설계 및 조정하고, 「제병협동작전 교육체계」를 개선하는데 유용하게 활용될 수 있을 것이다. The purpose of this study is to suggest the best plan for the 「Combined Forces Education System」 and the curriculum design plan by improving the decision-making method and subject adjustment criteria and procedures at the curriculum planning stage. First, the three improvement plans were compared by applying AHP, and the best was selected. Next, the subject adjustment criteria were established by applying the Delphi technique. In addition, the curriculum design plan was presented by analyzing the appropriateness of the current curriculum according to the established adjustment criteria. The results of this study are as follows. First, 2 weeks of prior training and 4 weeks of comprehensive training were deduced as the best plan. Second, 96 hours of additional time are needed to implement the best plan. According to the results of reviewing the subjects provided in Army OAC based on subject adjustment criteria, additional hours of 166 hours for infantry schools, 174 hours for artillery schools, and 119 hours for armoured schools can be secured. The research methods and improvement measures proposed in this study can be useful for designing and coordinating the curriculum in the military and improving the 「Combined Forces Education System」.

Comprehensive profiling on soil microbiotas in rice paddy fields

Hyun Kim,Jongbum Jeon,Kiseok Lee,Yong-Hwan Lee 한국농약과학회 2018 한국농약과학회 학술발표대회 논문집 Vol.2018 No.10

Enhancement of the Oxygen Evolution Using a 21-μm-Thin c-Si Photoanode with a Nano-Pyramid Texture

Park, Min-Joon,Heo, Jong,Jee, Hongsub,Yu, Jin Young,Youn, Sungmin,Jeon, Kiseok,Lee, Jung-Ho,Jeong, Chaehwan The Electrochemical Society 2017 Journal of the Electrochemical Society Vol.164 No.14

<P>It is beneficial to reduce thickness of high-purity of c-Siwafer for cost-effective water splitting system based on silicon photoelectrode. However, a thin Si absorber causes insufficient absorption of light and it should be needed to solve problems. Here, a 21-mu m-thin Si photoanode for which a NiOx-coated silicon nanopyramid (SiNP) is employed is presented as a solution. The NiOx/n-SiNP structures improved the light absorption as well as the total number of catalytic sites to enable photo-oxidation reactions. A photocurrent of 7.7 mA/cm(2) was generated at the equilibrium potential of the OER (E-OER = 1.23 V vs. a reversible hydrogen electrode in a 1 M KOH solution). Also, the photoanode did not show any degradation over the 24 hr of a photoelectrochemical water-oxidation process. (c) 2017 The Electrochemical Society. All rights reserved.</P>

스마트 디바이스를 통한 사용자-감동-경험 시스템 제안

신익수(IkSu Shin),문정민(JungMin Moon),변다예(DaYeab Byen),정지수(JiSu Jung),편정호(JeonHo Pyeon),황세영(SeYoung Hwang),신창범(ChangBeom Shin),전기석(KiSeok Jeon) 한국HCI학회 2014 한국HCI학회 학술대회 Vol.2014 No.2

요즘 모든 스마트폰에 근거리 무선 통신(NFC) 기능을 탑재하여서 기기들이 나오고 있다. NFC는 아주 가까운 거리의 무선 통신을 위한 기술로 교통 카드 등에 많이 쓰이고 있는 일반화된 기술이다. 본 연구는 NFC 기술을 이용하여 특별한 감동의 선물과 메시지를 주는 사용자-감동-경험 시스템을 제안한다. 본 연구에서는 총 세 가지 컨셉을 제안한다. 첫째 일반 카드형태의 제품(청첩장, 선물카드, 크리스마스카드) 등에 부착하여 글을 읽는 아날로그적인 감성과 함께 동영상이나 사진 등을 재생하여 예상치 못한 효과를 줌으로써 감동을 배가 시키는 컨셉. 둘째 반지 케이스를 이용한 제품으로 케이스에 NFC 기술을 부착하여 연인들과 결혼 상대에게 반지를 줌과 동시 NFC 기능을 통해 특별한 내용의 메시지나 영상, 손 편지 등을 스마트폰 화면에 표시하여 감동을 배가 시키는 컨셉. 셋째는 선물 케이스 리본에 부착된 제품으로 포장된 선물 리본을 자연스럽게 풀면서 NFC Tag의 메시지를 전달 할 수 있게 해주어 감동을 주는 컨셉이다. 본 컨셉들 모두 휴머니즘과 감동을 주는 사용자-감동-경험 시스템으로 본 컨셉 시스템은 특허 출원 중에 있으며 프로토타입으로 제작하여 그 가능성을 검증하고자 하였다. Nowadays all smart phones Near Field Communication (NFC) capabilities of devices are coming equipped with hightech . NFC is a short distance wireless communication technology for the transportation card for a generalized technique that is widely used . Using NFC technology , this study presents and messages of special touches that user-impress-experience system is proposed. In this study, all three concepts is proposed. The first product in the form of regular cards ( cards, gift cards, Christmas cards ) attached to the article to read the analog sensibility with video or photos, and play an unexpected effect by giving the impression that the ship concept. Second ring case in the case of products using NFC technology by attaching the ring to marry couples and NFC capabilities simultaneously zoom and special content of messages or images, such as smart phones, hand letter on the screen to double the impression concept . Third present case the ribbon is attached to a ribbon wrapped gift products as naturally full of NFC Tag be able to deliver the message is the concept that impressed . Impressed with the concept of humanism that all user- impress -experience systems and patent-pending system is the concept to prototype to production was to validate the possibilities.

아날로그 모형 조각과 스마트 디바이스를 이용한 인터랙션 교구 제안

정수연(Suyeon Jung),김상훈(Sanghun Kim),나현웅(Hyunwoong Na),선우예지(Yeji Sunwoo),이건우(Gunwoo Lee),홍현지(Hyunjee Hong),신창범(Changbeom Shin),전기석(kiseok Jeon) 한국HCI학회 2014 한국HCI학회 학술대회 Vol.2014 No.2

본 연구의 컨셉은 아동 발달단계에서 필요한 만지기, 손가락질하기, 손으로 다루기, 쥐기 등의 다양한 촉각 경험을 평면의 사물 모형조각을 이용하고 스마트 디바이스와 연동하여 체험할 수 있도록 해준다. 또한 촉각 경험에 끝나지 않고 마치 사물이 움직이는듯한 인터랙션을 아동에게 보여줌으로써 아동의 상상력을 키워준다. 또한 교구를 사용함에 있어서 아동 혼자 사용하는 것이 아니라 아동의 부모나 조부모 등의 어른이 참여 가능하도록 하여 자연스럽게 아동과의 친밀감을 유도한다. 기존의 교구들은 한 가지 교구를 가지고 한 가지의 학습 및 놀이를 할 수 밖에 없는 한계를 가지고 있다. 하지만 본 컨셉은 그러한 한계를 넘어서 스마트 디바이스에서 제공하는 모바일 애플리케이션을 통해 다양한 놀이 및 학습 콘텐츠를 제공받을 수 있어서 한 가지 교구를 가지고 여러 가지 놀이 및 학습 콘텐츠의 업그레이드가 가능한 스마트 교구를 연구하였다. 또한 본 내용은 특허 출원 중에 있으며 프로토타입으로 제작하여 사용자 경험적 측면에서 가능성을 검증하고 있다. The concept of this study require touching the child"s development stage, to finger, hand handle, grip, and more tactile experience, a piece of a plane object models used in conjunction with smart devices and allows you to experience. The tactile experience does not end things just by showing the animated children"s interactions with the child"s imagination gives raised. Also, in using the educational material children to use alone as well as the child"s parents or grandparents to be involved with an adult child with naturally leads to intimacy. Existing educational material with the parish one kind and one kind of learning not only to play has limitations. However, the concept of smart devices beyond those limits provided by the play and learning through a variety of mobile applications, providing content to receive one kind of the educational material has several play and learning content that can be upgraded with smart educational material was investigated. In addition, this patent-pending information and to prototype production possibilities in terms of the user verification is empirical.