• Title/Summary/Keyword: Intrinsic Mobility

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Electrical Properties of ZnTe:Cu Films Grown by Hot-Wall Evaporation (열벽 증착(hot-wall evaporaton) 방법으로 성장한 ZnTe:Cu 박막의 전기적 특성)

  • Park, S.G.;Nam, S.G.;O, B.S.;Lee, K.S.
    • Solar Energy
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    • v.17 no.3
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    • pp.51-57
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    • 1997
  • Cu-doped ZnTe thin films have been grown by hot-wall evaporation. The electrical conductivity of the intrinsic ZnTe film was of p-type and as low as $10^{-6}({\Omega}{\cdot}cm)^{-1}$. As the doped Cu concentration was increased, the electrical conductivity was increased. up to $10^2({\Omega}{\cdot}cm)^{-1}$, but the mobility was decreased a little. The heavily doped sample shows the metal-like electrical resistivity.

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Synthesis of Graphene Using Polystyrene and the Effect of Boron Oxide on the Synthesis of Graphene (폴리스타이렌을 이용한 그래핀 합성 및 산화 붕소가 그래핀 합성에 미치는 영향)

  • Choi, Jinseok;An, Sung Jin
    • Korean Journal of Materials Research
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    • v.28 no.5
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    • pp.279-285
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    • 2018
  • Graphene is an interesting material because it has remarkable properties, such as high intrinsic carrier mobility, good thermal conductivity, large specific surface area, high transparency, and high Young's modulus values. It is produced by mechanical and chemical exfoliation, chemical vapor deposition (CVD), and epitaxial growth. In particular, large-area and uniform single- and few-layer growth of graphene is possible using transition metals via a thermal CVD process. In this study, we utilize polystyrene and boron oxide, which are a carbon precursor and a doping source, respectively, for synthesis of pristine graphene and boron doped graphene. We confirm the graphene grown by the polystyrene and the boron oxide by the optical microscope and the Raman spectra. Raman spectra of boron doped graphene is shifted to the right compared with pristine graphene and the crystal quality of boron doped graphene is recovered when the synthesis time is 15 min. Sheet resistance decreases from approximately $2000{\Omega}/sq$ to $300{\Omega}/sq$ with an increasing synthesis time for the boron doped graphene.

A Study on the Methods of Spatial Composition in the Works of Carlo Mollino - Based on the analysis of conceptual investigations and design strategies - (카를로 몰리노의 공간구성 방식에 관한 연구 - 주요 작품의 개념적 전제와 계획적 전략을 중심으로 -)

  • Kim, Il-Hyun
    • Journal of the Korean housing association
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    • v.18 no.6
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    • pp.115-123
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    • 2007
  • This study aims to analyse the method and strategy of spatial composition in the selective works of Italian architect Carlo Mollino. With the continuos renovation of the interpretative frames and method on modernity and in particular on the spatial phenomenon, works of Mollino, once disregarded by the historiography and evaluated for its peculiarity. emerge as important architectural phenomenons. The intrinsic value in his works also enable to comprehend the complexity and multiplicity of modernity in contemporary architecture. In order to achieve this preposition, six important works were analyzed with three key words, to understand comprehensively the process and the significance of each work and Mollino's contribution in the spatial composition of domestic and public spaces. Evaluation of the spatial strategies in conceptual investigations of Mollino had been underestimated to the relative poor conservation or incomprehension of various work, excluded from the categories of architectural elaborations. This study also aims to contribute, in the broad sense, the dialectical significance of modernity by emphasizing the aspects of his work related with Surrealism and vernacular tradition, as well as with its relationship with the various spatial dispositives.

Investigation of contact resistance between metal electrodes and amorphous gallium indium zinc oxide (a-GIZO) thin-film transistors

  • Kim, Woong-Sun;Moon, Yeon-Keon;Lee, Sih;Kang, Byung-Woo;Kwon, Tae-Seok;Kim, Kyung-Taek;Park, Jong-Wan
    • 한국정보디스플레이학회:학술대회논문집
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    • 2009.10a
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    • pp.546-549
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    • 2009
  • In this paper, we investigated the effects of different source/drain (S/D) electrode materials in thin film transistors (TFTs) based on indium-gallium-zinc oxide (IGZO) semiconductor. A transfer length and effective resistances between S/D electrodes and amorphous IGZO thin-film transistors were examined. Intrinsic TFT parameters were extracted by the transmission line method (TLM) using a series of TFTs with different channel lengths measured at a low drain voltage. The TFTs fabricated with Cu S/D electrodes showed the lowest contact resistance and transfer length indicating good ohmic characteristics, and good transfer characteristics with a field-effect mobility (${\mu}_{FE}$) of 10.0 $cm^2$/Vs.

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MEMBRANES FOR GAS AND LIQUID SEPARATIONS

  • Golemme, Giovanni;Bove, Lucia;Clarizia, Gabriele;Muzzalupo, Rita;Ranieri, Giuseppe;Nam, Sang-Yong;Drioli, Enrico
    • Proceedings of the Membrane Society of Korea Conference
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    • 1999.07a
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    • pp.27-30
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    • 1999
  • Poly(phenylene oxide)s were used to prepare flat, integrally skinned self-supporthed asymmetric membranes by dry-wet phase separption. The intrinsic ideal gas selectivity of poly- (2,6-dimethy-1,4-phenylene oxide) (PMPO) was retained in the membranes, and improved by a coating with silicone rubber. Polymers of the same class were coated of UF supports with a silicon rubber gutter layer, yielding composite membranes with high flux but lower selectivity. The effect of th glutaraldehyde cross-linking of sodium alginate (SA) membranes on the mobility of water and ethanol has been studied with pfg nmr. Crosslinking reduces water self-diffusion, and does not seem to be stable on the timescale of weeks.

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A Study on the Design Method of Hybrid MOSFET-CNTFET based SRAM (하이브리드 MOSFET-CNTFET 기반 SRAM 디자인 방법에 관한 연구)

  • Geunho Cho
    • Journal of IKEEE
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    • v.27 no.1
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    • pp.65-70
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    • 2023
  • More than 10,000 Carbon NanoTube Field Effect Transistors (CNTFETs), which have advantages such as high carrier mobility, large saturation velocity, low intrinsic capacitance, flexibility, and transparency, have been successfully integrated into one semiconductor chip using conventional semiconductor design procedures and manufacturing processes. Three-dimensional multilayer structure of the CNTFET semiconductor chip and various CNTFET manufacturing process research increase the possibility of making the hybrid MOSFET-CNTFET semiconductor chip which combines conventional MOSFETs and CNTFETs together in a semiconductor chip. This paper discusses a methodology to design 6T binary SRAM using hybrid MOSFET-CNTFET. By utilizing the existing MOSFET SRAM or CNTFET SRAM design method, we will introduce a method of designing a hybrid MOSFET-CNTFET SRAM and compare its performance with the conventional MOSFET SRAM and CNTFET SRAM.

Chemical Analysis and Thermoelectric Properties of the PbSnTe Semiconductors (화학조성에 따른 PbSnTe계 반도체의 열전특성조사)

  • Oh, Kyu-Whan;Oh, Seung-Mo
    • Applied Chemistry for Engineering
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    • v.1 no.1
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    • pp.83-90
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    • 1990
  • The semiconducting $(Pb_1\;_xSn_x)_1$ $_yTe_y$, one of the low - temperature thermoelectric materials, has been prepared and its chemical composition and nonstoichiometry has been analyzed. The content of Pb in the specimens was determined by the complexometric back - titration method with EDTA and Pb(II) standard solutions. Te - content was analyzed with the redox titration method. The electrical conductivity and the thermoelectric power have also been measured by the DC 4 - probe and the heat-pulse technique, respectively. All of the specimens showed a nonstoichiometric behavior in their chemical compositions (Te excess), thus gave rise to a p - type semiconducting property, and the nonstoichoimetry became bigger as the Sn - content increased. The thermoelectric power vs. temperature results have been analyzed upon the basis of the Fermi level vs. temperature profiles in the saturation regime. The specimen of x=0.1 evolved a transition from p - to n - type property at about 670K, which has been explained by the fact that the mobility of electrons is bigger than that of holes in the temperature range of the intrinsic regime.

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Growth of CdS Single Crystal as Photoconductor and Its Physical Characteristics (광전도체의 CdS 단결정 성장과 물리적 특성)

  • Jeong, T.S.;Yu, P.Y.;Shin, Y.J.;Shin, H.K.;Kim, T.S.;Jeong, C.H.;Lee, H.;Shin, Y.S.;Hong, K.J.;Rheu, K.S.
    • Journal of Sensor Science and Technology
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    • v.2 no.1
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    • pp.109-115
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    • 1993
  • A CdS single crystal was grown by using sublimation method. Lattice constants, $a_{o}$ and $c_{o}$, obtained by using extrapolation were $4.131{\underline{8}}{\AA}$ and $6.712{\underline{2}}{\AA}$, respectively. The carrier density was${\sim}10^{23}m^{-3}$ and the mobility was $2.93{\times}10^{-2}m^{2}$/V sec from measured Hall data at room temperature. The mobility has a increasing tendency in proportion to $T^{1/2}$ from 33 K to 150 K and a decreasing tendency in proportion to $T^{-2}$ from 180 K to room temperature. The short wavelength band peak measured from photocurrent was due to intrinsic transition, and the energy value of this peak was equal to the energy band gap of CdS photoconductor.

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Neurobiology and Neurobiomechanics for Neural Mobilization (신경가동성에 대한 신경생물학과 신경생역학적 이해)

  • Kim Jae-Hun;Yuk Goon-Chan;Bae Sung-Soo
    • The Journal of Korean Physical Therapy
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    • v.15 no.2
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    • pp.67-74
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    • 2003
  • Nervous system is clinically important, and involved in most disorders directly or indirectly. It could be injury and be a source of symptoms. Injury of central or peripheral nervous system injury may affect that mechanism and interrupt normal function. An understanding of the concepts of axonal transport is important for physical therapist who treat injury of nerves. Three connective tissue layers are the endoneurium, perineurium, epineurium. Each has its own special structural characteristics and functional properties. The blood supply to the nervous system is well equipped in all dynamic and static postures with intrinsic and extrinsic vasculation. After nerve injury, alternations in the ionic compression or pressures within this environment may interfere with blood flow and, consequently conduction and the flow of axoplasm. The cytoskeleton are not static. On the contrary, elements of the cytoskeleton are dynamically regulated and are very likely in continual motion. It permits neural mobility. There are different axonal transport systems within a single axon, of which two main flows have been identified : First, anterograde transport system, Secondly, retrograde transport system. The nervous system adapts lengthening in two basic ways. The one is that the development of tension or increased pressure within the tissues, increased intradural pressure. The other is movements that are gross movement and movement occurring intraneurally between the connective tissues and the neural tissues. In this article, we emphasize the biologic aspects of nervous system that influenced by therapeutic approaches. Although identified scientific information in basic science is utilized at clinic, we would attain the more therapeutic effects and develop the physical therapy science.

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Load-Balancing Rendezvous Approach for Mobility-Enabled Adaptive Energy-Efficient Data Collection in WSNs

  • Zhang, Jian;Tang, Jian;Wang, Zhonghui;Wang, Feng;Yu, Gang
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.14 no.3
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    • pp.1204-1227
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    • 2020
  • The tradeoff between energy conservation and traffic balancing is a dilemma problem in Wireless Sensor Networks (WSNs). By analyzing the intrinsic relationship between cluster properties and long distance transmission energy consumption, we characterize three node sets of the cluster as a theoretical foundation to enhance high performance of WSNs, and propose optimal solutions by introducing rendezvous and Mobile Elements (MEs) to optimize energy consumption for prolonging the lifetime of WSNs. First, we exploit an approximate method based on the transmission distance from the different node to an ME to select suboptimal Rendezvous Point (RP) on the trajectory for ME to collect data. Then, we define data transmission routing sequence and model rendezvous planning for the cluster. In order to achieve optimization of energy consumption, we specifically apply the economic theory called Diminishing Marginal Utility Rule (DMUR) and create the utility function with regard to energy to develop an adaptive energy consumption optimization framework to achieve energy efficiency for data collection. At last, Rendezvous Transmission Algorithm (RTA) is proposed to better tradeoff between energy conservation and traffic balancing. Furthermore, via collaborations among multiple MEs, we design Two-Orbit Back-Propagation Algorithm (TOBPA) which concurrently handles load imbalance phenomenon to improve the efficiency of data collection. The simulation results show that our solutions can improve energy efficiency of the whole network and reduce the energy consumption of sensor nodes, which in turn prolong the lifetime of WSNs.