• Title/Summary/Keyword: Potential barrier

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Improvement of the On-Current for the Symmetric Dual-Gate TFT Structure by Floating N+ Channel

  • LEE, Dae-Yeon;Hwang, Sang-Jun;Park, Sang-Won;Sung, Man-Young
    • 한국정보디스플레이학회:학술대회논문집
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    • 2005.07a
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    • pp.342-344
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    • 2005
  • We have simulated a symmetric dual-gate TFT which has triple floating n+ channel to improve the on-current of the dual-gate TFT. We achieved a low hole concentration at the source and channel junction causes the improvement the potential barrier so that we observed the reduction of the kink-effect. In this paper, we observed the reduction of the kink-effect compared with the conventional single-gate TFT and the improvement of the on-current compared with the conventional dual-gate TFT.

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Influence of the Conduction Properties on ZnO-Based Ceramic Varistor with $TiO_2$ Additives ($TiO_2$의 첨가가 ZnO계 세라믹 바리스타에 미치는 전기적인 영향)

  • Lee, S.S.;Jang, K.U.;Lee, J.U.
    • Proceedings of the KIEE Conference
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    • 1987.11a
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    • pp.234-238
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    • 1987
  • In this paper, the used specimen composition was added basic additives ($Bi_2O_3\;lmol%$, $Sb_2O_3\;lmol%$, CoO 0.5 mol%, MnO 0.5mol%) to ZnO powder, and $TiO_2$ (1,2,3,4 mol%) to the above basic composition. It appears that there are four regions of conduction current depended upon the strength of the applied electric field ; Ohimic region, Poole-Frenkel region, Schottky region and Tunneling region. Increasing of $TiO_2mol%$, the breakdown voltages of ZnO ceramic varistors are decreased. The decrease of breakdown voltages was explained with the decrease of potential barrier height. Moreover, V-I characteristics with temperature dependence are decreased with increasing of $TiO_2mol%$.

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Potential Barrier Shift Caused by Channel Charge in Short Channel GaAs MESFET (Short Channel GaAs MESFET의 채널전하분포와 채널전하에 의한 전위장벽의 변화)

  • Sub, Won-Chang;Lee, Myung-Soo;Ryu, Se-Hwan;Han, Deuk-Young;Ahn, Hyung-Keun
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.19 no.9
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    • pp.793-799
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    • 2006
  • In this paper, the gate leakage current is first calculated using the experimental method between gate and drain by opening source electrode. the gate to drain current has been obtained with ground source. The difference between two currents has been tested and proves that the electric field generated by channel charge effect against the image force lowering.

A study on microstructure and electrical properties of LPCVD polysilicon (다결정 실리톤의 미세구조와 전기적 특성에 관한 연구)

  • 이은구;문대규;정호영
    • Electrical & Electronic Materials
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    • v.5 no.3
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    • pp.310-319
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    • 1992
  • LPCVD 방법으로 625.deg.C와 560.deg.에서 증착한 다결정 실리콘에 As이온주입량을 lx$10^{13}$-lx$10^{16}$/$cm^{2}$로 변화시키면서 열처리 전, 후의 미세구조와 전기적 특성 변화를 조사하였다. 625.deg.C에서 증착한 시편은 columnar구조를 하고 있어 표면이 매우 거칠었으며 900.deg.C, 30분 열처리 후에는 As doping 농도에 관계없이 결정립 크기는 200-300.angs.정도였다. 560.deg.C에서 증착한 시편은 비정질 상태로열처리 후에는 1000.angs.이상의 큰 결정립을 갖는 타원형의 결정립으로 성장하였으며 표면이 매우 smooth하였다. 같은 doping 농도에서 전기 전도도와 Hall mobility는 비정질 상태로 증착한 시편이 큰 결정립으로 인하여 다결정 상태로 증착한 시편에 비해 크게 되었다. Grain boundary trapping model에 의해 계산한 potential barrier height는 As doping 농도가 증가함에 따라 감소하였으며 grain boundary trap density는 증착 온도, As doping 농도 및 결정립 크기에 크게 관계없이 3.6~5*$10^{12}$/$cm^{2}$로 측정되었다.

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Space Charge Effects at Doped Ⅲ-Ⅴ Compound Semiconductor Interfaces (Doping된 Ⅲ-Ⅴ族 化合物 半導體 界面에서 空間電荷效果)

  • Chun, Jang-Ho
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.27 no.2
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    • pp.93-97
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    • 1990
  • Interfacil charge approximations and structures at doped semiconductor interfaces were proposed. Rectifying phenomena at the III-V compound semiconductor (p-GaP, p-InP, n-GaAs)/$CsNO_3$ aqueous electrolyte interfaces were qualitatively analyzed in terms of their cyclic current-voltage characteristics. The current-voltage characteristic curves, the ion adsorption and potential barrier processes at the semiconductor interfaces were verified using continuous cyclic voltammetric methods. The pn or np junction structures and the related rectifying types at the doped semi-condudtor-electrolyte inferfaces are determined by the space charges.

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Ideal structure for tunneling magnetoresistance and spin injection into semiconductros: Ni(111)/BN/Co(111)

  • Arqum, Hashmi;Son, Jicheol;Hong, Jisang
    • Proceedings of the Korean Magnestics Society Conference
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    • 2013.12a
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    • pp.32-32
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    • 2013
  • Using the Vienna ab initio simulation package (VASP) incorporating van der Waals interaction, we have explored structural, adsorption, and magnetic properties of Ni(111)/BN/Co(111) systems. We have found that both Ni(111) and Co(111) layers shows half metallic state, while the spacer BN layer becomes weak metal for one monolayer (ML) thickness and an insulating barrier for two ML thickness. The half metallic states in both Ni(111) and Co(111) layers are robust because it is unchanged independently on the magnetic coupling of Ni(111) and Co(111). This finding suggests that the Ni(111)/BN/Co(111) systems can be utilized for perfect tunneling magnetoresistance system. Moreover, it can be applied for potential spin injecting into semiconductor in FM/semiconductor system due to the fact that the half metallic state in FM layers at the interface will be unchanged.

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Identification of a Deoxyribonuclease I Inhibitor from a Phage-Peptide Library

  • Choi, Suk-Jung;Sperinde, Jeffrey J.;Szoka, Francis C. Jr.
    • Molecules and Cells
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    • v.19 no.1
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    • pp.54-59
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    • 2005
  • Deoxyribonuclease I (DNase I) is a divalent cation dependent endonuclease and thought to be a significant barrier to effective gene delivery. The only known DNase I-specific inhibitor is monomeric actin which acts by forming a 1:1 complex with DNase I. Its use, however, is restricted because of tendency to polymerize under certain conditions. We screened two random phage peptide libraries of complexity $10^8$ and $10^9$ for DNase I binders as candidates for DNase I inhibitors. A number of DNase I-binding peptide sequences were identified. When these peptides were expressed as fusion proteins with Escherichia coli maltose binding protein, they inhibited the actin-DNase I interaction ($IC_{50}=0.1-0.7{\mu}M$) and DNA degradation by DNase I ($IC_{50}=0.8-8{\mu}M$). Plasmid protection activity in the presence of DNase I was also observed with the fusion proteins. These peptides have the potential to be a useful adjuvant for gene therapy using naked DNA.

ESTIMATION OF CAKE FORMATION ON MICROFILTRATION MEMBRANE SURFACE USING ZETA POTENTIAL

  • Alayemieka, Erewari;Lee, Seock-Heon;Oh, Jeong-Ik
    • Environmental Engineering Research
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    • v.11 no.4
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    • pp.201-207
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    • 2006
  • A simple empirical model with good quantitative prediction of inter-particle and intra-particle distance in a cake layer with respect to ionic strength was developed. The model is an inverse length scale with functions of interaction energy and hydrodynamic factor and it explains that the inter-particle and intra-particle distance in a cake is directly related to the effective size of particles. Particle compressibility with respect to ionic strength was also predicted by the model. The model corroborated very well with experimental results of polystyrene microsphere latex particles microfiltation in a dead end operation. From the results of the model, specific cake resistance could be controlled by the same variables affecting the height of particle energy barrier described by the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory.

Establishment of Visible & Invisible Factors for FRT Design (FRT 디자인을 위한 가시적, 비가시적 요인 구축)

  • Han Suk-Woo
    • Proceedings of the KSR Conference
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    • 2004.10a
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    • pp.1701-1706
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    • 2004
  • FRT design aims at high-tech vehicles of high efficiency and cleanness, it must materialize the meaning and role as new added value by applying car design aesthetics of a new future-oriented concept. In addition, different from ordinary vehicle design, FRT involves invisible factors such as pleasantness, safety, accessibility, controllability, movability, conveniency, culture, identity, brand image and fashionableness. Because FRT vehicles are transportation means used by various groups of people, they must be approached with the barrier-free design concept. Therefore, in order to enhance the potential of future transportation culture emphasizing creativity based on diversity, it is important to establish core design factors that create new added values and to apply new concepts to their roles.

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Theoretical Study of Cycloaddition Reactions of C60 on the Si(100)-2×1 Surface

  • Rashid, Mohammad Harun Or;Lim, Chul-Tack;Choi, Cheol-Ho
    • Bulletin of the Korean Chemical Society
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    • v.31 no.6
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    • pp.1681-1688
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    • 2010
  • Density functional theory was adopted to study the various surface products and their reaction channels focusing on the on-dimer configuration which has not been suggested before. Energetic results show that the most stable on-dimer configuration is the 6,6-[2+2] structure which resembles the typical [2+2] cycloaddition product. The 6,6-[2+2] product is also more stable than any other possible surface structures of inter-dimer configuration further suggesting its existence. Potential energy surface scan along various possible initial surface reactions show that some of the possible on-dimer surface products require virtually no reaction barrier indicating that initial population of on-dimer surface products is thermodynamically determined. Various surface isomerization reaction channels exist further facilitating thermal redistribution of the initial surface products.