Graphene/Pentacene Barristor with Ion-Gel Gate Dielectric: Flexible Ambipolar Transistor with High Mobility and On/Off Ratio

Oh, Gwangtaek,Kim, Jin-Soo,Jeon, Ji Hoon,Won, EunA,Son, Jong Wan,Lee, Duk Hyun,Kim, Cheol Kyeom,Jang, Jingon,Lee, Takhee,Park, Bae Ho American Chemical Society 2015 ACS NANO Vol.9 No.7

<P>High-quality channel layer is required for next-generation flexible electronic devices. Graphene is a good candidate due to its high carrier mobility and unique ambipolar transport characteristics but typically shows a low on/off ratio caused by gapless band structure. Popularly investigated organic semiconductors, such as pentacene, suffer from poor carrier mobility. Here, we propose a graphene/pentacene channel layer with high-k ion-gel gate dielectric. The graphene/pentacene device shows both high on/off ratio and carrier mobility as well as excellent mechanical flexibility. Most importantly, it reveals ambipolar behaviors and related negative differential resistance, which are controlled by external bias. Therefore, our graphene/pentacene barristor with ion-gel gate dielectric can offer various flexible device applications with high performances.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/ancac3/2015/ancac3.2015.9.issue-7/acsnano.5b02616/production/images/medium/nn-2015-02616w_0005.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nn5b02616'>ACS Electronic Supporting Info</A></P>

High-mobility two-dimensional electron gas at the PbZr0.5Ti0.5O3/BaSnO3 heterostructure

Hwang Jaejin,Byun Jinho,Kim Hyejung,Lee Jaekwang 한국물리학회 2024 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.84 No.1

The two-dimensional electron gas (2DEG) formed at the oxide heterointerface between LaAlO3 (LAO) and SrTiO3 (STO) has gained signifcant attention due to its exotic physical properties and interfacial conductivity. However, the 2DEG resides in a weakly dispersive Ti-d band, resulting in relatively low mobility. This limitation hampers its practical applications in future oxide electronics. To enhance the mobility of the 2DEG, we propose the use of BaSnO3 (BSO) as a novel host material with a highly dispersive conduction Sn-5 s band. The s orbitals in BSO are signifcantly more delocalized than d orbitals, leading to a higher dispersion of the conduction band. Our frst-principles density functional theory (DFT) calculations reveal that a high-mobility n-type 2DEG can indeed be formed near the PbZr0.5Ti0.5O3/BSO interface. The polar feld of the ferroelectric PbZr0.5Ti0.5O3 generates an interfacial conducting state in BSO, resulting in a high-mobility n-type 2DEG within the highly dispersive Sn-5 s band.

공예와 디자인의 공존을 위한 하이테크 디자인 툴의 적용에 대한 연구

이진원(Lee, Jin Won) 한국디지털디자인협의회 2013 디지털디자인학연구 Vol.13 No.4

첨단 디지털 시대에 사는 현대인들은 텔레비전, 오디오, 휴대폰, 자동차 등 기계화, 디지털화로 대량생산된 제품들에 둘러싸여 있다. 이렇듯 첨단화된 양산제품들에 길들여져 있는 현대인들은 최근 첨단의 기능성 이외에 자신을 나타낼 수 있는 특별한 그 무엇을 갈망하고 있다. 이러한 갈망은 대량생산된 양산제품에서 결여된 섬세한 수공의 철학을 향한 것이다. 공예의 수공은 이러한 사람들이 갈망하는 특별함을 충족시키는 잠재성을 가지고 있다. 이러한 시점에서 본 연구에서는 공예의 영역 확장, 디자인과 공예의 공존 시도와 새로운 비전을 제시하기 위하여 디지털 제품에 공예의 수공을 적용하여 공예적인 마인드로 제작된 하이 엔드 휴대폰을 제안하였다. 공예와 디자인의 공존의 필요성에 대한 문헌연구와 디자인 방향 설정을 위한 연구로서 공예적 특성이 반영된 제품의 성공사례 연구와 전문가 인터뷰를 통하여 착용이 가능한 반지 형태의 하이 엔드 휴대폰이라는 새로운 콘셉트의 디자인 방향을 결정한 후 하이테크 디자인 툴을 적극 이용하여 디자인을 발전시켰다. 시행착오가 많은 수작업에 있어서 3D 소프트웨어와 Rapid Prototyping의 이용은 디자인 결과를 쉽게 예측할 수 있었다. 이러한 하이테크 디자인 툴의 사용은 디자인을 수정 보완 발전시키는 각 단계에서 디자인 결과와 제품의 구조, 크기와 위치를 쉽고 빠르게 예측해봄으로써 보다 정확했고, 수작업에 있어 시행착오를 획기적으로 줄일 수 있었으며, 작업시간 역시 획기적으로 단축시킬 수 있었다. Our generation is surrounded by mass produced products. Television, audio, mobile phones, automobiles take major portion of our lives and people are craving for a special something that could represent their individuality, differentiating themselves from the wide spread technologies. This thirst is for the delicate philosophy of craft that cannot be found in mass produced products. The manual work of craft has the potential to quench this longing for distinction. With this backdrop, I aimed to develop a handicraft high-end mobile phone conceived from the mind of a craft. This product will have the finest handmade quality, in a limited edition, embedded with a complete function to capture the minds of the users. Based on the above definition of a high-end product, a new concept of high-end mobile phone was devised for high-income consumer segment with young sense; a wearable ring-shape mobile phone. This phone can satisfy both the pleasure and the functional conveniences. Once the direction for design was established, design development was made by actively using high-tech design tool. It was easier to make predictions with 3D software and Rapid prototyping. On the bases of this prospected result, exact size and position of the panel and parts were calculated prior to metal work to minimize trials and errors. The high-tech design tool’s quicker and easier design forecast enhanced accuracy compared to manual modeling and thereby shortened total work hour. The high-end mobile phone with a new concept and design was conceived with an aspiration of a craft.

Cytoplasmic translocation of high-mobility group box-1 protein is induced by diabetes and high glucose in retinal pericytes

Kim, Junghyun,Kim, Chan-Sik,Sohn, Eunjin,Kim, Jin Sook SPANDIDOS PUBLICATIONS 2016 MOLECULAR MEDICINE REPORTS Vol. No.

<P>The aim of the present study was to assess the involvement of the high-mobility group box-1 (HMGB1) protein, receptor for advanced glycation end products (RAGE) and nuclear factor (NF)-κB signaling pathway in the development of diabetic retinopathy. Rat primary retinal pericytes were exposed to 25 mmol/l D-glucose for 48 h. Diabetic retinal vessels were prepared from streptozotocin-induced diabetic rats 12 weeks following the induction of diabetes. The expression of HMGB1 was detected using immunofluorescence staining. The expression of RAGE and the activity of NF-κB were analyzed using western blot and electrophoretic mobility shift assays, respectively. The results showed that HMGB1 was translocated to the cytoplasm of the high glucose-treated pericytes and diabetic retinal pericytes, whereas, in the control cells and the normal retinas, HMGB1 was expressed in the cell nuclei only. The expression of RAGE, a potential receptor for HMGB1, and the activity of NF-κB were also increased in the high glucose-treated pericytes, compared with the normal control cells. In addition, high glucose increased the binding of NF-κB to the RAGE promoter. These findings suggested that the cytoplasmic translocation of HMGB1 may be caused by diabetes and high glucose in retinal pericytes, and that the pathogenic role of HMGB1 may be dependent on the expression of RAGE and activation of NF-κB.</P>

고이동도 TFTs 구현에 nc-Si:H 박막의 수소 희석비와 결정성이 미치는 영향

최지원,김태용,팜뒤풍,조재웅,최자양,신동욱,이준신 한국전기전자재료학회 2021 전기전자재료학회논문지 Vol.34 No.4

TFTs technologies with as high mobility as possible is essential for high-performance large displays. TFTs using nanocrystalline silicon thin films can achieve higher mobility. In this work, the change of the crystalline volume fraction at different hydrogen dilution ratios was investigated by depositing nc-Si:H thin films using PECVD. It was observed that increasing hydrogen dilution ratio increased not only the crystalline volume fraction but also the crystallite size. The thin films with a high crystalline volume fraction (55%) and a low defect density (1017 cm-3⋅eV-1) were used as top gate TFTs channel layer, leading to a high mobility (55 cm2/V⋅s). We suggest that TFTs of high mobility to meet the need of display industries can be benefited by the formation of thin film with high crystalline volume fraction as well as low defect density as a channel layer.

고도 모빌리티 시대, 지구적 장소윤리를 위하여

김태희 서강대학교 인문과학연구소 2022 서강인문논총 Vol.- No.65

In the era of high mobility, the sense of place in the classical sense has been increasingly shaken. Assuming that ethics, a requirement for intersubjective existence, is impossible without a true sense of place, losing the sense of place makes the ethical relations between individuals temporary and unstable. Based on the reflection on place by phenomenologists and humanistic geographers, this article examines what place means for humans, how place changes and the sense of place is experienced, and how new ethics of place can be imagined in the era of high mobility. To this end, this article will explore ways to overcome the limitations of traditional concepts of place and establish global ethics of place, primarily focusing on the concept of the global sense of place. Finally, in conclusion, this article briefly considers the possibility of establishing an ethics of place based on the vulnerability in the era of high mobility. 고도 모빌리티(high mobility) 시대에는 고전적 의미의 장소감(sense of place)이 동요한다. 상호주관적 존재의 필요조건인 윤리가 진정한 장소감 없이는 불가능하다는 것을 전제한다면, 이러한 장소감의 동요는 윤리적 관계를 일시적이고 불안정하게 만든다. 본고는 장소에 관한 현상학과 인본주의 지리학의 성찰을 기초로 하여, 인간에게 있어 장소는 어떤 의미인지, 고도 모빌리티 시대에 장소는 어떻게 변화하고 장소감은 어떻게 체험되며 새로운 장소윤리(ethics of place)는 어떻게 상상될 수 있는지 검토한다. 이를 위해 특히 지구적 장소감(global sense of place) 개념을 중심으로 전통적인 장소 개념의 한계를 극복하고 지구적 장소윤리(global ethics of place)를 확립하는 방안을 모색할 것이다. 마지막으로 결론에서는 고도 모빌리티 시대에 취약성에 기초한 장소윤리를 확립할 가능성을 간략히 전망하고자 한다.

초고속 무선인터넷에서 인구통계적 요인이 폰형과 모뎀형 선택에 끼치는 영향에 관한 연구

류귀열 한국자료분석학회 2011 Journal of the Korean Data Analysis Society Vol.13 No.2

본 연구는 인구통계적 요인이 이동전화 초고속 무선인터넷, 와이브로 등을 이용할 때 사용하는 단말기의 선택에 끼치는 영향에 관한 연구이다. 초고속 무선인터넷은 무선 인터넷의 전송속도가 대략 1Mbps 이상을 말하는 서비스로서, 단말기로는 음성전화와 겸용으로 사용하는 타입을 폰형, 음성전화를 사용하지 않고 무선데이터 전용으로 사용하는 타입을 모뎀형으로 정의하였다. 폰형과 모뎀형에 따라 서비스 형태도 달라지기 때문에 중요한 문제이다. 로짓분석과 로지스틱분석에 의하면 나이, 결혼유무, 성별, 학력, 직업, 가구소득 등 모든 요인들은 폰형과 모뎀형을 선택하는 데 유의한 영향을 주는 것으로 나타났다. 결혼유무와 성별에 관계없이 폰형을 선호하였으나 나이가 많을수록, 학력이 높을수록, 고소득 직업일수록, 가구소득이 높을수록 모뎀형을 선호하는 비율이 증가하는 패턴을 보이고 있다는 사실을 밝혔다. 본 연구에 따르면 스마트폰과 같은 폰형은 젊은 그룹을 타겟으로, 모뎀형은 나이가 많고 고소득인 그룹을 타겟으로 마케팅활동을 전개하는 것이 효과적이라 추정된다. The object of study is how demographic factors affect subscribers' behavior on selecting device for high speed mobile internet. The devices for a high speed mobile internet are a cellular phone, a smart phone, a PDA, a PMP, a sub notebook computer, and a notebook computer. We will call the mobile device with voice as the phone type, and the mobile device without voice as the modem type. The selection of the type is a very important problem because speed, a window size, service types, and service rates of mobile internet are depending on the type of device. The demographic factors which we research are age, marriage, academic ability, vocation, and household income. All factors affect selecting device. A result we find is that the percentage of selecting phone type is decreasing as age is increasing, academic ability is high, the income level of vocation is high, and household income is high.

모빌리티 적용 영구자석형 고출력 모터 설계 기술

이정종,윤명환,이기덕 한국자기학회 2023 韓國磁氣學會誌 Vol.33 No.4

Mobility motors have various applications such as automobiles, aircraft, small mobile devices, and UAM, but their common characteristics are small and high-powered. This paper explains how to apply permanent magnets to increase power density from the point of view of electromagnetic system design, change the characteristics of permanent magnets, and how to use them focusing on electric vehicles and electric aircraft motors applied to mobility motors that are recently increasing. In addition, an axial flux motor capable of realizing a high-output motor was introduced. Permanent magnets applied to high-power motors have various problems of current input and high temperature, therefore the change in the operation point of permanent magnet according to the change of the permanent magnet and the surrounding magnetic circuit has been described. Accordingly, the characteristics of permanent magnets to avoid irreversible demagnetization were discussed. High-powered axial flux motors were introduced to currently applied aircraft and motors, and the loss reduction of iron cores considered in designing motors was explained.

Ultra-high-resolution printing of flexible organic thin-film transistors

Xuying Liu,Masayuki Kanehara,Chuan Liu,Takeo Minari 한국정보디스플레이학회 2017 Journal of information display Vol.18 No.2

Fully printed electronics on plastic have attracted considerable interest owing to their high compatibility and ease of integration. Here, an ultra-high-resolution printing technique based on parallel vacuum ultraviolet patterning that can produce high-contrast wettability regions on flexible substrates was developed. This technique was used to selectively deposit a functional ink with a 1μm feature size, thereby allowing the large-scale fabrication of organic thin-film transistors with channels as short as 1μm under an ambient atmosphere. Moreover, in short-channel devices, hole injection barriers can be tuned by printing the optimum gate overlaps associated with selectively doping semiconductor/electrode interfaces, resulting in a marked reduction in contact resistance from 20 to 1.5, and an elevation of the charge carrier mobility to a record high of 0.3 cm2 V−1 s−1 in a 1-μm-channel device. The results indicate that the developed technique is promising for the fabrication of large-area, high-resolution, low-cost electronics.

대량화학요법을 위한 G-CSF를 이용한 말초조혈모세포의 구동

김삼용,조덕연 충남대학교 의과대학 지역사회의학연구소 1999 충남의대잡지 Vol.26 No.2

This study probed the effective and economic method for mobilizing the hemopoietic stem cells for the support of high-dose chemotherapy. Eleven trials of Hemopoietic mobilization was performed in 10 patients. A total of 36 leukapheresis was performed(median; 3, range; 2 - 6). Cytotoxic chemotherapy plus G-CSF(300μg/day x 7 days) or G-CSF alone was given to mobilize hemopoietic stem cells. A median of 5.4 x (3.3 - 9.47) x 10 ^8/kg mononuclear cells and 5.1(1.3 - 43) x 10^4/kg GM-CFU was obtained. Nine courses of high-dose chemotherapy was performed in 8 patients. Days with absolute neutrophil count less than 1000/㎣ was 8.5(range ; 3-26) and days with platelet count less than 50.000/㎣ was 14(range; 0-46). Days G-CSF required was 12.5(range ; 9-27) and a median of 100units(range; 10-250) of platelet transfusion was required. Days with antibiotic coverage was 7. 5(0-30) and days of admission was 24(range; 17-51). We can conclude in this study that cyclophosphamide 2g/㎡ and G-CSF 300μg x 7days, or G-CSF for 7 days arc sufficient for the mobilization of hemopoietic stem cells for the high-dose chemotherapy.