Graphene's low intrinsic carrier concentration necessitates extrinsic doping to enhance its conductivity and improve its performance for application as electrodes or transparent conductors. Despite this importance limited knowledge of the doping process at application-relevant conditions exists. Employing in-situ carrier transport and Raman characterization of different dopants, we here explore the fundamental mechanisms limiting the effectiveness of doping at different doping levels. Three distinct transport regimes for increasing dopant concentration could be identified. First the agglomeration of dopants into clusters provides a route to increase the graphene conductivity through formation of ordered scatterers. As the cluster grows, the charge transfer efficiency between graphene and additional dopants decreases due to emerging polarization effects. Finally, large dopant clusters hinder the carrier motion and cause percolative transport that leads to an unexpected change of the Hall effect. The presented results help identifying the range of beneficial doping density and guide the choice of suitable dopants for graphene's future applications.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4663794 | PMC |
| http://dx.doi.org/10.1038/srep17393 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Development of a model for detection and analysis of inclusions in tomographic images of iron castings using decision trees.
Sci Rep
January 2025
Department of Applied Computer Science and Modelling Department, Faculty of Metals Engineering and Industrial Computer Science, AGH University of Krakow, Czarnowiejska 66, 30-054, Krakow, Poland.
CT images of castings made of ductile iron were analyzed in the paper. On these images, objects can be identified that can be considered as graphite precipitates or indicate the presence of a defect in the casting. Research conducted in this area is described, based on experimental data that allows to determine whether the indicated components present in the casting are graphite precipitation.
View Article and Find Full Text PDFSpontaneous heat current and ultra-high thermal rectification in asymmetric graphene: a molecular dynamics simulation.
Nanotechnology
January 2025
Department of Electrical and Computer Engineering, Nazarbayev University, Nazarbayev University, Astana, Kazakhstan, Astana, 010000, KAZAKHSTAN.
Non-equilibrium molecular dynamics (NEMD) simulations reveal the existence of a spontaneous heat current (SHC) in the absence of a temperature gradient and demonstrate ultra-high thermal rectification in asymmetric trapezoid-shaped graphene. These unique properties have potential applications in power generation and thermal circuits, functioning as thermal diodes. Our findings also show the presence of negative and zero thermal conductivity in this system.
View Article and Find Full Text PDFNano-confined Si@C composites with excellent lithium-ion storage performance derived from a POSS-based covalent framework and low-temperature reduction method.
Dalton Trans
January 2025
State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210023, China.
Silicon-based anode materials experience significant volume changes and low conductivity during the lithiation process, which severely hinders their successful application in lithium-ion batteries. Reducing the size of silicon particles and effectively combining them with carbon-based materials are considered the main strategies to enhance the lithium-ion storage performance of silicon-based anodes. In this study, we employed a "bottom-up" strategy to synthesize Si@C anode materials by cross-linking octa-aminopropyl polyhedral oligomeric silsesquioxane (NH-POSS) with terephthalaldehyde and subsequent high-temperature treatment and low-temperature liquid reduction.
View Article and Find Full Text PDFOvercoming the Conductance versus Crossover Trade-off in State-of-the-Art Proton Exchange Fuel-Cell Membranes by Incorporating Atomically Thin Chemical Vapor Deposition Graphene.
Nano Lett
January 2025
Interdisciplinary Graduate Program in Materials Science, Vanderbilt University, Nashville, Tennessee 37235, United States.
Permeance-selectivity trade-offs are inherent to polymeric membranes. In fuel cells, thinner proton exchange membranes (PEMs) could enable higher proton conductance and increased power density with lower area-specific resistance (ASR), smaller ohmic losses, and lower ionomer cost. However, reducing thickness is accompanied by an increase in undesired species crossover harming performance and long-term efficiency.
View Article and Find Full Text PDFNanoscopic Supercapacitance Elucidations of the Graphene-Ionic Interface with Suspended/Supported Graphene in Different Ionic Solutions.
ACS Appl Mater Interfaces
January 2025
Graduate Institute of Electronics Engineering, National Taiwan University, Taipei 10617, Taiwan.
Graphene-based supercapacitors have gained significant attention due to their exceptional energy storage capabilities. Despite numerous research efforts trying to improve the performance, the challenge of experimentally elucidating the nanoscale-interface molecular characteristics still needs to be tackled for device optimizations in commercial applications. To address this, we have conducted a series of experiments using substrate-free graphene field-effect transistors (SF-GFETs) and oxide-supported graphene field-effect transistors (OS-GFETs) to elucidate the graphene-electrolyte interfacial arrangement and corresponding capacitance under different surface potential states and ionic concentration environments.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!