• Title/Summary/Keyword: Field effect

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Fabrication of Silicon Nanowire Field-effect Transistors on Flexible Substrates using Direct Transfer Method (전사기법을 이용한 실리콘 나노선 트랜지스터의 제작)

  • Koo, Ja-Min;Chung, Eun-Ae;Lee, Myeong-Won;Kang, Jeong-Min;Jeong, Dong-Young;Kim, Sang-Sig
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2009.06a
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    • pp.413-413
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    • 2009
  • Silicon nanowires (Si NWs)-based top-gate field-effect transistors (FETs) are constructed by using Si NWs transferred onto flexible plastic substrates. Si NWs are obtained from the silicon wafers using photolithography and anisotropic etching process, and transferred onto flexible plastic substrates. To evaluate the electrical performance of the silicon nanowires, we examined the output and transfer characteristics of a top-gate field-effect transistor with a channel composed of a silicon nanowire selected from the nanowires on the plastic substrate. From these FETs, a field-effect mobility and transconductance are evaluated to be $47\;cm^2/Vs$ and 272 nS, respectively.

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The Approach for the Trade-off Study Between Field-effect Mobility and Current on/off Ratio in P3HT Field-effect Transistors

  • Jeong, Shin-Woo;Chang, Seong-Pil;Park, Jung-Ho;Oh, Tae-Yeon;Ju, Byeong-Kwon
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.25 no.1
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    • pp.15-19
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    • 2012
  • Presented herein are the results of the study that was conducted on the electrical characteristics of organic field-effect transistors based on poly(3-hexylthiophene), particularly the thickness and annealing temperature of their active layer is varied. The changes in field-effect mobility and current on/off ratio were explored. It was observed that both increasing annealing temperature from $60^{\circ}C$ to $100^{\circ}C$ and various concentrations influence the trade-off relations between the mobility and current on/off ratio. The surface morphology of the 2-${\mu}m^2$ area with various thicknesses was scanned via atomic-forcemicroscopy(AFM) to verify the relationship between surface morphology, which is related to the thickness of the film, and device performance.

Fabrication of Etched Graphene/CuO Nanowires as Field Effect Transistors

  • Hien, Vu Xuan;Kim, Se-Yun;Kim, MyeongEon;Lee, Joon-Hyung;Kim, Jeong-Joo;Heo, Young-Woo
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.02a
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    • pp.430-430
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    • 2013
  • Field effect transistor based on semiconductor nanowires has been attracting lots of concerns and studies of scientists because of its different characteristic comparing with other morphology like thin film. Nowadays, graphene is introducing a great promise as an active layer in field effect transistor due to its unique electronic and optoelectronic properties. Thus, a mix structure between etched graphene and semiconductor nanowires is believed to expose novel electrical characteristics. In this study, CuO nanowires (20~80 nm in diameter and $1{\sim}10{\mu}m$ length) were grown during oxidizing Cu foil at $450^{\circ}C$ for 24 h. Besides, 3-layersetched graphene was deposited on Cu foil at $1,000^{\circ}C$ using a feedstock of $CH_4$/$H_2$ mixed gas in CVD system. A structure of Ni/Au electrode + CuO nanowires + etched graphene was fabricated, afterward. Finally, field effect properties of the device was revealed and compared with individual devices of just nanowires and just graphene.

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The Productivity Impact of Working from Home and the Moderating Effect of Task Characteristics: An Empirical Investigation of Field Data (재택근무가 업무 생산성에 미치는 영향과 업무 특성의 조절 효과: 대규모 현장 데이터를 활용한 실증 분석)

  • Jae-Young Kim;Dong-Joo Lee
    • Asia-Pacific Journal of Business
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    • v.15 no.1
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    • pp.113-129
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    • 2024
  • Purpose - This study aims to empirically identify the quantitative effects of work from home (WFH) on employee productivity using field data. Design/methodology/approach - Based on large-scale field data from a South Korean company which introduced the WFH arrangement in 2020, we conducted fixed effect and moderating effect analyses using individual-level panel data over sixty-three weeks. Findings - The empirical analysis generated several findings. It was found that overall, WFH has a positive effect on productivity. However, the productivity impact of WFH was found to vary depending on task characteristics. Specifically, WFH led to over 20% increase in productivity for simple and repetitive tasks. On the other hand, no significant productivity impact was observed for professional and knowledge-based tasks. Research implications or Originality - As the first study based on field data from South Korea, this study offers convincing causal evidence of the moderating impact of task characteristics on the relationship between WFH and productivity. Further, the above findings provide managers with practical insights concerning their work arrangement decisions.

The Moderating Effects of Field-dependence and Field-independence Cognitive Style of Learning Satisfaction of Digital Textbook (디지털교과서의 학습만족에 대한 장의존 및 장독립적 인지양식의 조절효과 검증)

  • Kim, Soo-Min
    • Journal of Digital Convergence
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    • v.8 no.3
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    • pp.79-93
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    • 2010
  • This study aims to verify whether field-dependence and field-independence cognitive style have regulatory effect or not on information quality and system quality of digital textbooks in learning satisfaction. In order to accomplish the purpose, the research was carried out with 325 students of digital textbook research school who are fifth and sixth grade at a primary school living in Seoul metropolitan city. Results from the verification of hypotheses are as follows: when learning satisfaction of digital textbooks is affected by information quality and system quality influence satisfaction, it is given a positive moderating effect by the variables of field-dependence and field-independence cognitive style.

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The Effect of External DC Electric Field on the Atmospheric Corrosion Behaviour of Zinc under a Thin Electrolyte Layer

  • Liang, Qinqin;YanYang, YanYang;Zhang, Junxi;Yuan, Xujie;Chen, Qimeng
    • Corrosion Science and Technology
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    • v.17 no.2
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    • pp.54-59
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    • 2018
  • The effect of external DC electric field on atmospheric corrosion behavior of zinc under a thin electrolyte layer (TEL) was investigated by measuring open circuit potential (OCP), cathodic polarization curve, and electrochemical impedance spectroscopy (EIS). Results of OCP vs. time curves indicated that the application of external DC electric field resulted in a negative shift of OCP of zinc. Results of cathodic polarization curves measurement and EIS measurement showed that the reduction current of oxygen increased while charge transfer resistance ($R_{ct}$) decreased under the external DC electric field. Variation of OCP negative shift, reduction current of oxygen, and $R_{ct}$ increase with increasing of external DC electric field strength as well as the effect of external DC electric field on double-layer structure in the electrode/electrolyte interface and ions distribution in thin electrolyte layer were analyzed. All results showed that the external DC electric field could accelerate the corrosion of zinc under a thin electrolyte layer.

Numerical Evaluation of charged Liquid Particle′s Behavior in Fluid Flow and Electric Field and The Electric Effect on the Particle Dispersion (유동과 전기장 내에서의 액체입자의 거동과 전기장이 입자의 산란에 미치는 영향에 관한 수치적 연구)

  • Kim, Hyeong-Min
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.26 no.4
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    • pp.570-577
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    • 2002
  • Charged liquid particle's behavior in electric and flow field was simulated to define the effect of electric field on the contact area and its dispersion. For the simulation of flow and electric field finite volume method was applied. To find out the particle's moving path in that field lagrangian equation of motion was solved by Runge-Kutta methods. We assumed that the particle was charged 10% of Rayleigh limit while the particle passing through the electrode and the particle does not have an effect on the electric field. In case of 30[Kv] of voltage charging the particles injected from the central 60% of the nozzle injection area adhere to the grounded moving plate and no dispersion occurred. Increasing the charged voltage to 40[Kv], it brought about the same phenomena as that of 30[Kv] charging except the dispersion. Voltage increasing from 30[Kv] to 40 [Kv] caused higher Coulomb force acts on the particle and it made the particle dispersion.

An Analysis of the Effectiveness on Rural Field Forum - Focusing on the recognition change and satisfaction of the inhabitants - (농촌현장포럼 효과분석 - 주민의 인식 변화 및 만족도를 중심으로 -)

  • Kwon, Dong-Geon;Jang, Woo-Whan
    • Journal of Korean Society of Rural Planning
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    • v.21 no.4
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    • pp.13-26
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    • 2015
  • This study was conducted to analyze the policy impacts of the '2014 Rural Field Forum'. From 2013, Ministry of Agriculture, Food and Rural Affairs implemented Rural Field Forum to push forward rural development of inhabitants' initiative. In this study, we have evaluated that Rural Field Forum has crucial impacts on residents' competence, region capability and driving force of project by targeting the 374 residents of 350 villages in 9 states who participated in 2014 Rural Field Forum. We also sought for the solution to institutional improvement. Futhermore we analyzed each of leader group and normal residents for departmentalization of policy effects. Taken together, the analysis reveals that: 1)Rural field forum is demonstrated to have a positive effect on the establishment and execution of village development plan and all of its necessary components. 2)Regarding the effect on the village capabilities, the understanding and recognition of village organization was shown to be improved. 3)About regional capabilities, the interest in village project was advanced. 4)In terms of the project execution, Rural field forum turned out to affect the village council processes positively. 5)lastly, between the leader and the residents, the difference effectiveness between them revealed, with the same directivity and considerably bigger effect felt by the leader than by the residents overall.

An Analysis of the Flow Field and Radiation Acoustic Field of Centrifugal Fan with Wedge -The Prediction of the Scattered Sound Field- (웨지가 있는 원심 임펠러의 유동장 및 방사 음향장 해석(II) -원심홴의 산란 음향장 예측-)

  • Lee, Deok-Ju;Jeon, Wan-Ho
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.25 no.9
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    • pp.1165-1174
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    • 2001
  • The objective of this study is to understand the generation mechanism of sound and to develop a prediction method for the acoustic pressure field of a centrifugal fan. If the fan is operating at the free field without the casing, the acoustic analogy is a good method to predict the acoustic of the fan. But, the casing gives a dominant effect to the radiated sound field and the scattering effect of casing should be considered. So, in this paper the Kirchhoff-BEM is developed, which can consider the scattering effect of the rigid body. In order to consider the scattering and diffraction effects owing to the casing, BEM is introduced. The source of BEM is newly developed, so the sound field of the centrifugal fan can be obtained. In order to compare the predicted one with experimental data, a centrifugal impeller and a wedge are used in the numerical calculation and the results are compared with the experimental data. Reasonable results are obtained not only for the peak frequencies but also for the amplitudes of the tonal sound. The radiated acoustic field shows the diffraction and scattering effects of the wedge clearly.

Effect of Current-Aging on Field Emission from Carbon Nanotube Field Emitter Arrays

  • Kim, Ki-Seo;Ryu, Je-Hwang;Lee, Chang-Seok;Manivannan, S.;Moon, Jong-Hyun;Ahn, Jung-Sun;Jang, Jin;Park, Kyu-Chang
    • 한국정보디스플레이학회:학술대회논문집
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    • 2007.08a
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    • pp.782-785
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    • 2007
  • We studied the effect of current-aging on field emission from carbon nanotubes field emitter arrays (CNT-FEAs) selectively patterned by the resist-assistan tpatterning(RAP) process. After sustaining the electric field when starting emission current density $(J_s)$ is $0.1\;mA/cm^2$ during 40 hrs, it was observed that the field emission property and uniformity were remarkably improved due to the elimination of oxygen atom and thus the reconstruction of carbon bonding at the tip of CNTs during field emission.

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