• Title/Summary/Keyword: Tunneling mechanism

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Investigation of Trap-Assisted-Tunneling Mechanism in L-Shaped Tunneling Field-Effect-Transistor (L형 터널 트랜지스터의 트랩-보조-터널링 현상 조사)

  • Najam, Faraz;Yu, Yun Seop
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2018.10a
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    • pp.512-513
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    • 2018
  • Trap-assisted-tunneling (TAT) degrades subthreshold slope of real-world tunneling field-effect-transistors (TFET) and it should be considered in the simulation. However, its mechanism is not very well understood in line tunneling type L-shaped TFET (LTFET). This study investigates TAT mechanism in LTFETs using dynamic nonlcoal Schenk model. Both phonon assisted and direct band to trap tunneling events are considered in this study.

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Investigation of Trap-Assisted-Tunneling Mechanism in L-Shaped Tunneling Field-Effect-Transistor at Low Bias (L형 터널 트랜지스터의 트랩-보조-터널링 현상 조사)

  • Najam, Faraz;Yu, Yun Seop
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2019.05a
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    • pp.475-476
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    • 2019
  • L-shaped tunneling field-effect-transistor (LTFET) is considered a superior device over conventional TFETs. However, experimentally demonstrated LTFET demonstrated poor subthreshold characteristics which was attributed to trap-assisted-tunneling (TAT) caused by presence of trap states. In this paper, TAT mechanism in the experimentally demonstrated LTFET is investigated with the help of band diagram and TAT recombination rate (GTAT).

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Effects of Tunneling Current on STM Imaging Mechanism for Alkanethiol Self-assembled Monolayers on Au(111)

  • Mamun, Abdulla Hel Al;Son, Seung-Bae;Hahn, Jae-Ryang
    • Bulletin of the Korean Chemical Society
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    • v.32 no.1
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    • pp.281-285
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    • 2011
  • We investigated the effects of tunneling current on scanning tunneling microscopy (STM) images of 1-octanethiol (OT) and 1-decanethiol (DT) self-assembled monolayers (SAMs). At a low tunneling current, the domain boundaries and ordered alkanethiol molecules were clearly resolved. As the tunneling current was increased at a constant bias voltage, however, the STM images showed disordered structures of the OT and DT SAMs. As the tunneling current was reduced back to low values, the ordered structures of the alkanethiol molecules reappeared. The reversibility of the process suggests that the sulfur head groups did not rearrange under any of the tunneling current conditions. On the basis of our observations, which are inconsistent with the standard model for STM imaging of molecules on metal surfaces, we consider the STM imaging mechanism in terms of a two-region tunneling junction model.

Current-Voltage Characteristics of Organic Light-Emitting Diodes with a Variation of Temperature (온도 변화에 따른 유기 전기 발광 소자의 전압-전류 특성)

  • Kim, Sang-Geol;Hong, Jin-Ung;Kim, Tae-Wan
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.51 no.7
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    • pp.322-327
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    • 2002
  • Temperature-dependent current-voltage characteristics of organic light-emitting diodes(OLEDs) were studied in a device structure of ITO/TPD/Alq$_3$/Al to understand conduction mechanism. The current-voltage characteristics were measured in the temperature range of 8K ~ 300K. We analyzed an electrical conduction mechanism of the OLEDS using space-charge-limited current(SCLC) and Fowler-Nordheim tunneling. In the temperature range above 150k, the conduction mechanism could be explained by space charge limited current from the inversely proportional temperature dependence of exponent m. The characteristic trap energy is found to be about 0.15ev. At low temperatures below 150k, the Fowler-Nordheim tunneling conduction mechanism is dominant. We have obtained a zero field barrier height to be about 0.6~0.8eV.

Dual-Tunneling Mechanism for Supporting Host Mobility between Heterogeneous Access Networks (이종 접속 망간의 단말 이동성 지원을 위한 이원적 터널 기법)

  • Choi, Young-Hwan;Kim, Yeon-Jung;Yu, Fucal;Park, Soo-Chang;Kim, Sang-Ha
    • Journal of KIISE:Information Networking
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    • v.36 no.1
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    • pp.43-49
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    • 2009
  • The Mobile IPv6(MIPv6) has a well-known time gap of packet loss between link down and binding update. To minimize such packet loss, this paper proposes a MIPv6-based dual tunneling mechanism, which keeps exploiting the old tunnel while creating a new tunnel. Superiority of the proposed mechanism is evaluated by quantitative analysis on the lost packets and computer simulation, based on two overlay heterogeneous access networks, such as the UMTS and a WLAN.

Triple-gate Tunnel FETs Encapsulated with an Epitaxial Layer for High Current Drivability

  • Lee, Jang Woo;Choi, Woo Young
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.17 no.2
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    • pp.271-276
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    • 2017
  • The triple-gate tunnel FETs encapsulated with an epitaxial layer (EL TFETs) is proposed to lower the subthreshold swing of the TFETs. Furthermore, the band-to-band tunneling based on the maximum electric-field can occur thanks to the epitaxial layer wrapping the Si fin. The performance and mechanism of the EL TFETs are compared with the previously proposed TFET based on simulation.

Switching characteristics of the Scaled MONOS Nonvolatile Memory Devices (Scaled MONOS 비휘발성 기억소자의 스위칭 특성)

  • 이상배;김선주;이성배;강창수;서광열
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1995.05a
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    • pp.54-57
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    • 1995
  • This study is to investigate the switching charac-teritics in the5V-programmable scaled MONOS nonvolatile memory devices, Modified Folwer-Nordheim tunneling mechanism become important when the electric field in the tunneling oxide is 6 MV/cm for E$\_$OT/ <6MV/cm the trap-assisted tunneling mechanism is dominant, The density of nitride bulk trap is found to be N$\_$T/=7.7${\times}$10$\^$18/ cm$\^$-3/ and the energy level of trap is determined to be ø$\_$T/=0.65 eV.

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The DSTM TEP for IPv4 and IPv6 Interoperability (IPv4/IPv6의 연동을 위한 DSTM TEP의 기능)

  • 진재경;최영지;민상원
    • Journal of KIISE:Computing Practices and Letters
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    • v.9 no.5
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    • pp.578-587
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    • 2003
  • The DSTM (Dual Stack Transition Mechanism), one of tunneling mechanism, is considered as the best solution in IPv4/IPv6 transition recently. The DSTM provides a method to assure IPv4/v6 connectivity based on 4over6 (IPv4-over-IPv6) tunneling and temporal allocation of a global IPv4 address to a host requiring such communication. A TEP (Tunnel End Point) operates as a border router between IPv6 domain and IPv4 Internet, which performs encapsulation and decapsulation of 4over6 tunneling packets to assure hi-directional forwarding between both networks. In this paper, we analyze basic standards of the IPv6 protocol. And, we design and implement a DSTM TEP daemon block. The TEP daemon analyzes a fevers tunneling packet that is forwarded by the DSTM node, establishes the TEP's 4over6 interface, and supplies communication between a DSTM and a IPv4-only node. Finally, we construct a DSTM testbed and measure performance of the DSTM TEP. Our observation results show that performance of TEP supports the DSTM service.

Stress-Pore Pressure Coupled Finite Element Modeling of NATM Tunneling (NATM 터널의 응력-간극수압 연계 유한요소모델링)

  • Yoo, Chung-Sik;Kim, Sun-Bin
    • Proceedings of the Korean Geotechical Society Conference
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    • 2006.03a
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    • pp.189-198
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    • 2006
  • This paper concerns the finite element (FE) modeling approach for NATM tunneling in water bearing ground within the framework of stress-pore pressure coupled analysis. Fundamental interaction mechanism of ground and groundwater lowering was first examined and a number of influencing factors on the results of coupled FE analysis were identified. A parametric study was then conducted on the influencing factors such as soil-water characteristics, location of hydraulic boundary conditions, the way of modeling drainage flow, among others. The results indicate that the soil-water characteristics plays the most important role in the tunneling-induced settlement characteristics. Based on the results, modeling guidelines were suggested for stress-pore prssure coupled finite element modeling of NATM tunneling.

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Study on the Electrical Conduction Mechanism of Organic Light-Emitting Diodes (OLEDs) (유기발광소자(OLED)의 전기전도메커니즘에 대한 고찰)

  • Lee, Won Jae
    • Journal of the Semiconductor & Display Technology
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    • v.17 no.4
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    • pp.6-10
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    • 2018
  • Organic light emitting devices have attracted the attention of many people because of their high potential for self-emission and flexible display devices. However, due to limitations in device efficiency and lifetime, partial commercialization is underway. In this paper, we have investigated the electrical conduction mechanism of the organic light emitting device by the temperature and the thickness of the light emitting layer through the current - voltage characteristics with respect to the conduction mechanism directly affecting the efficiency and lifetime of the organic light emitting device. Through the study, it was found that the conduction in the low electric field region is caused by the movement of the heat excited charge in the ohmic region and the tunneling of the electric charge due to the high electric field in the high electric field region.