• Title/Summary/Keyword: Field effect

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Focused Electron Beam-Controlled Graphene Field-Effect Transistor

  • Kim, Songkil
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.33 no.5
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    • pp.360-366
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    • 2020
  • Focused electron beams with high energy acceleration are versatile probes. Focused electron beams can be used for high-resolution imaging and multi-mode nanofabrication, in combination with, molecular precursor delivery, in an electron microscopy environment. A high degree of control with atomic-to-microscale resolution, a focused electron beam allows for precise engineering of a graphene-based field-effect transistor (FET). In this study, the effect of electron irradiation on a graphene FET was systematically investigated. A separate evaluation of the electron beam induced transport properties at the graphene channel and the graphene-metal contacts was conducted. This provided on-demand strategies for tuning transfer characteristics of graphene FETs by focused electron beam irradiation.

Ambipolarity Factor of Tunneling Field-Effect Transistors (TFETs)

  • Jang, Jung-Shik;Choi, Woo-Young
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.11 no.4
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    • pp.272-277
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    • 2011
  • The ambipolar behavior of tunneling field-effect transistors (TFETs) has been investigated quantitatively by introducing a novel parameter: ambipolarity factor (${\nu}$). It has been found that the malfunction of TFET can result from the ambipolar state which is not on- or off- state. Therefore, the effect of ambipolar behavior on the device performance should be parameterized quantitatively, and this has been successfully evaluated as a function of device structure, gate oxide thickness, supply voltage, drain doping concentration and body doping concentration by using ${\nu}$.

Investigation on the Doping Effects on L-shaped Tunneling Field Effect transistors(L-shaped TFETs) (도핑효과에 의한 L-shaped 터널링 전계효과 트랜지스터의 영향에 대한 연구)

  • Shim, Un-Seong;Ahn, Tae-Jun;Yu, Yun Seop
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2016.05a
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    • pp.450-452
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    • 2016
  • The effect of channel doping on L-shaped Tunneling Field-Effect Transistors (TFETs) have been investigated by 2D TCAD simulation. When the source doping is over $10^{20}cm^{-3}$, the subthreshold swing (SS) is abruptly decreased, and when drain doping concentration is below $10^{18}cm^{-3}$, the leakage current in the negative voltage is reduced.

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Evaluation of the Alternatives to Minimize Stack Effect Problems with Elevators in Tall Complex Buildings (초고층 복합건축물 엘리베이터에서의 연돌현상 저감방안 평가)

  • Yu, Jung-Yeon;Song, Kyoo-Dong;Cho, Dong-Woo
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.21 no.2
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    • pp.118-125
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    • 2009
  • The purpose of this study is to evaluate the stack effect reduction alternatives in tall complex buildings in cold climates. The main problems in tall buildings occur in elevators. Such problems as elevator doors that do not close and exhaust airflows result in excessive pressure differences across elevator doors due to stack effect. Under the expected conditions causing these pressure differences, Field measurements are performed in three tall buildings. Each result of the measurements is analyzed in architectural design aspects. With these analysis, building design guidelines are proposed and analyzed by field measurements and computer simulations.

Integrated Circuits, Optics, and Sensors Using Organic Field Effect Transistors and Photodetectors

  • Kymissis, Ioannis
    • 한국정보디스플레이학회:학술대회논문집
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    • 2008.10a
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    • pp.1279-1282
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    • 2008
  • Organic field effect transistors are excellent candidates for addressing and local amplification elements for large area electronics because they can easily be processed at low temperatures on essentially arbitrary substrates. We present the use of these devices in an active matrix photodetector and as a buffer for a strain sensor.

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Vertical Type Organic Transistors and Flexible Display Applications

  • Kudo, Kazuhiro
    • 한국정보디스플레이학회:학술대회논문집
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    • 2007.08a
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    • pp.168-169
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    • 2007
  • Organic transistors are promising in the future development of active devices for flexible, low-cost and large-area photoelectric devices. However, conventional organic field-effect transistors have lowspeed, low-power, and relatively high operational voltage. Vertical type transistors show high-speed and high-current characteristics and are suitable for driver elements of flexible displays.

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The Development of Near-field Probing Method on the Base Station Array Antenna (기지국 배열안테나의 근역장 프로빙 방법의 개발)

  • Lim, Gye-jae
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.2 no.1
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    • pp.65-72
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    • 2009
  • For the evaluation of far-field performance by using the near-field probing on the base station dipole array antenna, the effects of mutual coupling depending on the heights between the array antenna with reflector and the probe were analyzed. When the height is varied in the near-field region, S parameters on the input ports of antenna and probe are measured and analyzed to decide the height for the minimum mutual coupling effect and the maximum probing efficiency. This height will be applicable to the near-field probing system design to achieve the precision far-field performance of a base station array antenna system.

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Strain Improvement of Yeast for Ethanol Production Using a Combined Treatment of Electric Field and Chemical Mutagen N-Methyl-N'-nitro-N- nitrosoguanidine

  • Kim, Keun;Lee, Jae-Yeon
    • Journal of Microbiology and Biotechnology
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    • v.8 no.2
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    • pp.119-123
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    • 1998
  • The feasibility of using combined treatments of electric field and chemical mutagen N-methyl-N'-nitro-N-nitroso-guanidine (NTG) for the strain improvement of Saccharomyces sp. in ethanol production was examined. The treatment of electric field alone resulted in no effect on the lethality of yeast cells under the conditions of this study. However, when the electric field was applied together to the treatment of yeast cells with NTG, the electric field increased the lethal effect and auxotrophic mutation rate of NTG. The combined treatment of electric field and NTG also increased the chances of. obtaining superior yeast strains for the ethanol production from tapioca. A higher number of improved clones was obtained by the combined treatments of electric field and NTG than by the NTG treatment alone. The best clone, NF 30-9, which was also obtained by the combined treatment, produced $11.07\%$ (w/v) ethanol from tapioca slurry containing 25% (w/v) reducing sugar while the parental strain produced 9.77% (w/v).

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Objective quantification of the impact of blepharoplasty on the superior visual field

  • Kim, Hyodong;Lee, Sanghun;Son, Daegu;Yeo, Hyeonjung
    • Archives of Plastic Surgery
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    • v.49 no.1
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    • pp.19-24
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    • 2022
  • Background Blepharoplasty has both aesthetic and functional benefits in patients with pseudoptosis; however, previous studies could not demonstrate its beneficial effects quantitatively and objectively. The authors objectively analyzed the visual field before and after surgery and investigated whether measurements of the visual field can be applied as a suitable predictor of surgical outcomes. Methods In total, 18 eyelids in nine patients with pseudoptosis who had undergone simple skin excision blepharoplasty were evaluated prospectively from February to May 2016. The visual fields were analyzed preoperatively and 3 months postoperatively using the Goldmann kinetic perimetry test. The visual field test area was assessed using Adobe Photoshop. Results Blepharoplasty had an average 4.99-fold beneficial effect on the superior visual field. In particular, more improvement was seen in the superior temporal quadrant than in the nasal quadrant. No correlation was found between the preoperative margin-to-reflex distance 1 (MRD1) and the surgical outcome (P=0.119). However, there was a strong correlation between the preoperative superior visual field and the surgical outcome (P=0.001). Conclusions Using the Goldmann kinetic perimetry test, we objectively and quantitatively proved the beneficial effect of blepharoplasty on patients with pseudoptosis. Furthermore, we demonstrated that the preoperative visual field is a better preoperative surgical outcome predictive factor than the preoperative MRD1.