Universal mobility characteristics of graphene originating from charge scattering by ionised impurities

AbstractPristine graphene and graphene-based heterostructures can exhibit exceptionally high electron mobility if their surface contains few electron-scattering impurities. Mobility directly influences electrical conductivity and its dependence on the carrier density. But linking these key transport parameters remains a challenging task for both theorists and experimentalists. Here, we report numerical and analytical models of carrier transport in graphene, which reveal a universal connection between graphene’s carrier mobility and the variation of its electrical conductivity with carrier density. Our model of graphene conductivity is based on a convolution of carrier density and its uncertainty, which is verified by numerical solution of the Boltzmann transport equation including the effects of charged impurity scattering and optical phonons on the carrier mobility. This model reproduces, explains, and unifies experimental mobility and conductivity data from a wide range of samples and provides a way to predict a priori all key transport parameters of graphene devices. Our results open a route for controlling the transport properties of graphene by doping and for engineering the properties of 2D materials and heterostructures.

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Time-resolved Photoconductivity as a Probe of Carrier Transport in Microcrystalline Silicon

MRS Proceedings ◽

10.1557/proc-0910-a01-01 ◽

2006 ◽

Vol 910 ◽

Author(s):

Steve Reynolds

Keyword(s):

Density Of States ◽

Carrier Mobility ◽

Carrier Transport ◽

Film Growth ◽

Hole Mobility ◽

Transport Parameters ◽

Microcrystalline Silicon ◽

Time Resolved ◽

Transient Photoconductivity ◽

Transport Measurements

AbstractThe use of transient photoconductivity techniques in the investigation of carrier transport in microcrystalline silicon is described. Results are presented which highlight variations in transport parameters such as carrier mobility and density of states with structure composition. Hole mobility is significantly enhanced by crystalline content in the film of 10% or less. The density of states inferred from transport measurements parallel to and at right angles to the direction of film growth differ somewhat, suggesting that transport may be anisotropic.

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Field Effect Mobility of F16PcCu Films in Various Gas Atmospheres

Journal of Porphyrins and Phthalocyanines ◽

10.1002/(sici)1099-1409(199908/10)3:6/7<667::aid-jpp191>3.0.co;2-y ◽

1999 ◽

Vol 03 (07) ◽

pp. 667-671 ◽

Cited By ~ 10

Author(s):

HIROKAZU TADA ◽

HIROSHI TOUDA ◽

MASAKI TAKADA ◽

KAZUMI MATSUSHIGE

Keyword(s):

Carrier Density ◽

Field Effect ◽

Carrier Mobility ◽

Carrier Transport ◽

Room Temperature ◽

Gas Adsorption ◽

Quick Recovery ◽

Thermally Activated ◽

High Carrier ◽

Gas Molecules

The electron mobility of hexadecafluorophthalocyaninato-copper ( F 16 PcCu ) films was evaluated based on field effect measurements in vacuum and in various gas atmospheres. An Arrhenius plot of the mobility showed that the carrier transport followed a thermally activated hopping mechanism with an activation energy of 0.28 eV. The mobility evaluated for freshly prepared films in ultrahigh vacuum was 2.0 × 10−3 cm 2 V −1 s −1 at room temperature. The electrical conductivity and carrier density were 4.4 × 10−5 S cm −1 and 1.4 × 1017 cm −3 respectively. The high carrier density indicated the existence of impurities acting as electron donors in the films. The field effect carrier mobility increased to 5.7 × 10−3 cm 2 V −1 s −1 in NH 3 atmosphere (100%, 1 atm) and decreased by 75% in the presence of O 2 gas (100%, 1 atm). A quick recovery of mobility was observed when the gas molecules were evacuated, indicating a low capability of gas adsorption.

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Partial Carbonization of Aromatic Polyimide Films

MRS Proceedings ◽

10.1557/proc-593-289 ◽

1999 ◽

Vol 593 ◽

Author(s):

M. Doyama ◽

A. Ichida ◽

Y. Inoue ◽

Y. Kogure ◽

T. Nozaki ◽

...

Keyword(s):

Experimental Data ◽

Electrical Conductivity ◽

Hall Coefficient ◽

Carrier Density ◽

Carrier Mobility ◽

Absolute Temperature ◽

Polyimide Films ◽

Aromatic Polyimide ◽

The Absolute

ABSTRACTAromatic polyimide films are partially carbonized between 700°C and 1000°C. Electrical conductivity and Hall coeficient have been measured. Electrical conductivity is higher at higher measuring temperatures. The electrical conductivity σ can be expressed as σ= σ0exp (–E /kT), where k is the Boltzman constant. T is the absolute temperature. E depends upon the carborized temperature. The experimental data show the Hall coefficient RH is negative, and this implies the carriers are negatively charged, i.e. electrons. The specimens are n-type semiconductors. The carrier density η can be expressed by η= A1 exp (–E1/κT) and carrier mobility μ can be expressed by μ = A1exp ( E2/κT). E, E1andE2 depend upon the carbonized temperature

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High electrical conductivity and carrier mobility in oCVD PEDOT thin films by engineered crystallization and acid treatment

Science Advances ◽

10.1126/sciadv.aat5780 ◽

2018 ◽

Vol 4 (9) ◽

pp. eaat5780 ◽

Cited By ~ 59

Author(s):

Xiaoxue Wang ◽

Xu Zhang ◽

Lei Sun ◽

Dongwook Lee ◽

Sunghwan Lee ◽

...

Keyword(s):

Thin Films ◽

Electrical Conductivity ◽

Radio Frequency Identification ◽

Acid Treatment ◽

Carrier Mobility ◽

Carrier Transport ◽

Great Promise ◽

High Electrical Conductivity ◽

High Carrier Mobility ◽

High Carrier

Air-stable, lightweight, and electrically conductive polymers are highly desired as the electrodes for next-generation electronic devices. However, the low electrical conductivity and low carrier mobility of polymers are the key bottlenecks that limit their adoption. We demonstrate that the key to addressing these limitations is to molecularly engineer the crystallization and morphology of polymers. We use oxidative chemical vapor deposition (oCVD) and hydrobromic acid treatment as an effective tool to achieve such engineering for conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT). We demonstrate PEDOT thin films with a record-high electrical conductivity of 6259 S/cm and a remarkably high carrier mobility of 18.45 cm2V−1s−1by inducing a crystallite-configuration transition using oCVD. Subsequent theoretical modeling reveals a metallic nature and an effective reduction of the carrier transport energy barrier between crystallized domains in these thin films. To validate this metallic nature, we successfully fabricate PEDOT-Si Schottky diode arrays operating at 13.56 MHz for radio frequency identification (RFID) readers, demonstrating wafer-scale fabrication compatible with conventional complementary metal-oxide semiconductor (CMOS) technology. The oCVD PEDOT thin films with ultrahigh electrical conductivity and high carrier mobility show great promise for novel high-speed organic electronics with low energy consumption and better charge carrier transport.

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Predicting Electrokinetic Coupling and Electrical Conductivity in Fractured Media Using a Fractal Distribution of Tortuous Capillary Fractures

Applied Sciences ◽

10.3390/app11115121 ◽

2021 ◽

Vol 11 (11) ◽

pp. 5121

Author(s):

Luong Duy Thanh ◽

Damien Jougnot ◽

Phan Van Do ◽

Dang Thi Minh Hue ◽

Tran Thi Chung Thuy ◽

...

Keyword(s):

Electrical Conductivity ◽

Porous Media ◽

Streaming Potential ◽

Fractured Media ◽

Analytical Models ◽

Fractal Distribution ◽

Wide Range ◽

Surface Electrical Conductivity ◽

Water Saturated ◽

Fractal Size

Electrokinetics methods have attracted increasing interest to characterize hydrogeological processes in geological media, especially in complex hydrosystems such as fractured formations. In this work, we conceptualize fractured media as a bunch of parallel capillary fractures following the fractal size distribution. This conceptualization permits to obtain analytical models for both the electrical conductivity and the electrokinetic coupling in water saturated fractured media. We explore two different approaches to express the electrokinetic coupling. First, we express the streaming potential coupling coefficient as a function of the zeta potential and then we obtain the effective charge density in terms of macroscopic hydraulic and electrokinetic parameters of porous media. We show that when the surface electrical conductivity is negligible, the proposed models reduces to the previously proposed one based on a bundle of cylindrical capillaries. This model opens up a wide range of applications to monitor the water flow in fractured media.

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Defect Chemistry of “BaCuO2” II. Transport Properties and Nature of Defects

Zeitschrift für Naturforschung A ◽

10.1515/zna-1995-1113 ◽

1995 ◽

Vol 50 (11) ◽

pp. 1059-1066 ◽

Cited By ~ 1

Author(s):

G. Chiodelli ◽

U. Anselmi-Tamburini ◽

M. Arimondi ◽

G. Spinolo ◽

G. Flor

Keyword(s):

Electrical Conductivity ◽

Charge Transport ◽

Transport Properties ◽

Carrier Mobility ◽

Transport Number ◽

Ionic Transport ◽

Ionic Transport Number ◽

Wide Range ◽

Small Polarons ◽

Cation Ratio

Abstract The charge transport properties of "BaCuO2" with 88:90 (Ba :Cu) cation ratio were characterized by thermopower, electrical conductivity and ionic transport number measurements in a wide range of temperature and oxygen partial pressure conditions. The nature of carriers is always represented by small polarons due to self-trapping of the electronic holes generated by the oxygen non-stoichiometry equilibrium. Some anomalies in carrier mobility as a function of temperature are shown not to be related to incomplete ionization of oxygen atoms on interstitial sites

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Predicting Electrokinetic Coupling and Electrical Conductivity in Fractured Media Using a Bundle of Tortuous Capillary Fractures

10.20944/preprints202103.0206.v1 ◽

2021 ◽

Author(s):

Luong Duy Thanh ◽

Damien Jougnot ◽

Phan Van Do ◽

Dang Thi Minh Hue ◽

Tran Thi Chung Thuy ◽

...

Keyword(s):

Electrical Conductivity ◽

Porous Media ◽

Zeta Potential ◽

Streaming Potential ◽

Fractured Media ◽

Analytical Models ◽

Wide Range ◽

Surface Electrical Conductivity ◽

Water Saturated ◽

Fractal Size

The electrokinetics methods have a great potential to characterize hydrogeological processes in geological media, especially in complex hydrosystems such as fractured formations. In this work, we conceptualize fractured media as a bunch of parallel capillary fractures following the fractal size distribution. This conceptualization permits to obtain analytical models for both the electrical conductivity and the electrokinetic coupling in water saturated fractured media. We explore two different approaches to express the electrokinetic coupling. First, we express the streaming potential coupling coefficient as a function of the zeta potential and then we obtain the effective charge density in terms of macroscopic hydraulic and electrokinetic parameters of porous media. We show that when the surface electrical conductivity is negligible, the proposed models reduces to the previously proposed one based on a bundle of cylindrical capillaries. This model opens up a wide range of applications to monitor the water flow in fractured media.

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Multi-material braids for multifunctional laminates: conductive through-thickness reinforcement

Functional Composite Materials ◽

10.1186/s42252-021-00018-0 ◽

2021 ◽

Vol 2 (1) ◽

Author(s):

Caroline O’Keeffe ◽

Laura Rhian Pickard ◽

Juan Cao ◽

Giuliano Allegri ◽

Ivana K. Partridge ◽

...

Keyword(s):

Electrical Conductivity ◽

Carbon Fibre ◽

Electromagnetic Interference ◽

Design Tool ◽

Electrically Conductive ◽

Current Collection ◽

Wide Range ◽

Predictive Design ◽

The Right ◽

Metal Wires

AbstractConventional carbon fibre laminates are known to be moderately electrically conductive in-plane, but have a poor through-thickness conductivity. This poses a problem for functionality aspects that are of increasing importance to industry, such as sensing, current collection, inductive/resistive heating, electromagnetic interference (EMI) shielding, etc. This restriction is of course more pronounced for non-conductive composite reinforcements such as glass, organic or natural fibres. Among various solutions to boost through-thickness electrical conductivity, tufting with hybrid micro-braided metal-carbon fibre yarns is one of the most promising. As a well-characterised method of through thickness reinforcement, tufting is easily implementable in a manufacturing environment. The hybridisation of materials in the braid promotes the resilience and integrity of yarns, while integrating metal wires opens up a wide range of multifunctional applications. Many configurations can be produced by varying braid patterns and the constituting yarns/wires. A predictive design tool is therefore necessary to select the right material configuration for the desired functional and structural performance. This paper suggests a fast and robust method for generating finite-element models of the braids, validates the prediction of micro-architecture and electrical conductivity, and demonstrates successful manufacturing of composites enhanced with braided tufts.

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Development of Permeability Models for Saturated Fluid Flow across Arrays of Fibre Clusters

Advanced Composites Letters ◽

10.1177/096369350201100303 ◽

2002 ◽

Vol 11 (3) ◽

pp. 096369350201100

Author(s):

E.M. Gravel ◽

T.D. Papathanasiou

Keyword(s):

Analytical Models ◽

Dual Porosity ◽

Hydraulic Permeability ◽

Fibrous Media ◽

Fibre Bundles ◽

Hexagonal Packing ◽

Composites Manufacturing ◽

Starting Point ◽

Wide Range ◽

Flow Through

Dual porosity fibrous media are important in a number of applications, ranging from bioreactor design and transport in living systems to composites manufacturing. In the present study we are concerned with the development of predictive models for the hydraulic permeability ( Kp) of various arrays of fibre bundles. For this we carry out extensive computations for viscous flow through arrays of fibre bundles using the Boundary Element Method (BEM) implemented on a multi-processor computer. Up to 350 individual filaments, arranged in square or hexagonal packing within bundles, which are also arranged in square of hexagonal packing, are included in each simulation. These are simple but not trivial models for fibrous preforms used in composites manufacturing – dual porosity systems characterised by different inter- and intra-tow porosities. The way these porosities affect the hydraulic permeability of such media is currently unknown and is elucidated through our simulations. Following numerical solution of the governing equations, ( Kp) is calculated from the computed flowrate through Darcy's law and is expressed as function of the inter- and intra-tow porosities (φ, φt) and of the filament radius ( Rf). Numerical results are also compared to analytical models. The latter form the starting point in the development of a dimensionless correlation for the permeability of such dual porosity media. It is found that the numerically computed permeabilities follow that correlation for a wide range of φ i, φt and Rf.

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