scholarly journals Atomically Thin Mica Flakes and Their Application as Ultrathin Insulating Substrates for Graphene

Small ◽  
2011 ◽  
pp. n/a-n/a ◽  
Author(s):  
Andres Castellanos-Gomez ◽  
Magdalena Wojtaszek ◽  
Nikolaos Tombros ◽  
Nicolás Agraït ◽  
Bart J. van Wees ◽  
...  
Keyword(s):  
Thin Mica ◽  
Insulating Substrates

scholarly journals Critical View on Buffer Layer Formation and Monolayer Graphene Properties in High-Temperature Sublimation

2021 ◽  
Vol 11 (4) ◽  
pp. 1891
Author(s):  
Vallery Stanishev ◽  
Nerijus Armakavicius ◽  
Chamseddine Bouhafs ◽  
Camilla Coletti ◽  
Philipp Kühne ◽  
...  
Keyword(s):  
High Temperature ◽  
Charge Carrier ◽  
Buffer Layer ◽  
Free Charge Carrier ◽  
Monolayer Graphene ◽  
Free Charge ◽  
Layer Formation ◽  
Free Hole ◽  
Sublimation Growth ◽  
Insulating Substrates

In this work we have critically reviewed the processes in high-temperature sublimation growth of graphene in Ar atmosphere using closed graphite crucible. Special focus is put on buffer layer formation and free charge carrier properties of monolayer graphene and quasi-freestanding monolayer graphene on 4H–SiC. We show that by introducing Ar at higher temperatures, TAr, one can shift the formation of the buffer layer to higher temperatures for both n-type and semi-insulating substrates. A scenario explaining the observed suppressed formation of buffer layer at higher TAr is proposed and discussed. Increased TAr is also shown to reduce the sp3 hybridization content and defect densities in the buffer layer on n-type conductive substrates. Growth on semi-insulating substrates results in ordered buffer layer with significantly improved structural properties, for which TAr plays only a minor role. The free charge density and mobility parameters of monolayer graphene and quasi-freestanding monolayer graphene with different TAr and different environmental treatment conditions are determined by contactless terahertz optical Hall effect. An efficient annealing of donors on and near the SiC surface is suggested to take place for intrinsic monolayer graphene grown at 2000 ∘C, and which is found to be independent of TAr. Higher TAr leads to higher free charge carrier mobility parameters in both intrinsically n-type and ambient p-type doped monolayer graphene. TAr is also found to have a profound effect on the free hole parameters of quasi-freestanding monolayer graphene. These findings are discussed in view of interface and buffer layer properties in order to construct a comprehensive picture of high-temperature sublimation growth and provide guidance for growth parameters optimization depending on the targeted graphene application.

Direct growth of graphene on rigid and flexible substrates: progress, applications, and challenges

2017 ◽  
Vol 46 (20) ◽  
pp. 6276-6300 ◽  
Author(s):  
Viet Phuong Pham ◽  
Hyeon-Sik Jang ◽  
Dongmok Whang ◽  
Jae-Young Choi
Keyword(s):  
Performance Degradation ◽  
Flexible Substrates ◽  
Graphene Growth ◽  
Transfer Processes ◽  
Direct Growth ◽  
And Performance ◽  
Insulating Substrates

A review of various strategies, including transfer-free direct graphene growth on insulating substrates, which avoids the transfer processes that cause graphene defects, residues, tears and performance degradation in graphene-based functional devices. Applications and challenges of "direct growth of graphene'' in commercialization are discussed and addressed.

Electrical Properties of β-FeSi2 Thin Films on Insulating Substrates

2003 ◽  
Vol 796 ◽  
Author(s):  
Kensuke Akiyama ◽  
Takeshi Kimura ◽  
Shin Nishiyama ◽  
Takeo Hattori ◽  
Naoki Ohashi ◽  
...  
Keyword(s):  
Thin Films ◽  
Iron Silicide ◽  
Amorphous Film ◽  
Rf Magnetron Sputtering ◽  
Atomic Ratio ◽  
Similar Temperature Dependence ◽  
Electrical Conductivities ◽  
Similar Temperature ◽  
Band Conduction ◽  
Insulating Substrates

ABSTRACTIron silicide thin films were prepared on insulating substrates using RF magnetron sputtering method. Amorphous, polycrystalline and epitaxial β-FeSi2 were obtained on MgO(001), Al2O3(110) and Al2O3(001) substrates, respectively. Electrical conductivities of these films showed similar temperature dependence. Intrinsic band conduction and hopping conduction mechanism were predominant above and below 600K, respectively. The localized ordering in the polycrystalline and epitaxial films that controled the movement of carriers were as low as in the amorphous film. For the epitaxial β-FeSi2 film, electrical conductivity below 600K were affected by atomic ratio of silicon to iron (Si/Fe) in the films, because the localized ordering in the films decreased as Si/Fe atomic ratio decreased.

scholarly journals A 350 mK, 9 T scanning tunneling microscope for the study of superconducting thin films on insulating substrates and single crystals

2013 ◽  
Vol 84 (12) ◽  
pp. 123905 ◽  
Author(s):  
Anand Kamlapure ◽  
Garima Saraswat ◽  
Somesh Chandra Ganguli ◽  
Vivas Bagwe ◽  
Pratap Raychaudhuri ◽  
...  
Keyword(s):  
Thin Films ◽  
Single Crystals ◽  
Scanning Tunneling Microscope ◽  
Scanning Tunneling ◽  
Superconducting Thin Films ◽  
Tunneling Microscope ◽  
Insulating Substrates

scholarly journals Note: Long-range scanning tunneling microscope for the study of nanostructures on insulating substrates

2014 ◽  
Vol 85 (2) ◽  
pp. 026105 ◽  
Author(s):  
Aday J. Molina-Mendoza ◽  
José G. Rodrigo ◽  
Joshua Island ◽  
Enrique Burzuri ◽  
Gabino Rubio-Bollinger ◽  
...  
Keyword(s):  
Long Range ◽  
Scanning Tunneling Microscope ◽  
Scanning Tunneling ◽  
Tunneling Microscope ◽  
Range Scanning ◽  
Insulating Substrates

Large-scale nanoelectromechanical switches based on directly deposited nanocrystalline graphene on insulating substrates

Nanoscale ◽  
2016 ◽  
Vol 8 (12) ◽  
pp. 6659-6665 ◽  
Author(s):  
Jian Sun ◽  
Marek E. Schmidt ◽  
Manoharan Muruganathan ◽  
Harold M. H. Chong ◽  
Hiroshi Mizuta
Keyword(s):  
Large Scale ◽  
Insulating Substrates

scholarly journals Calculating free energies of organic molecules on insulating substrates

2017 ◽  
Vol 8 ◽  
pp. 667-674
Author(s):  
Julian Gaberle ◽  
David Z Gao ◽  
Alexander L Shluger
Keyword(s):  
Free Energy ◽  
Organic Molecules ◽  
Computational Cost ◽  
Potential Of Mean Force ◽  
Free Energies ◽  
Energy Profiles ◽  
Integration Techniques ◽  
Ring Structures ◽  
Anchoring Groups ◽  
Insulating Substrates

The challenges and limitations in calculating free energies and entropies of adsorption and interaction of organic molecules on an insulating substrate are discussed. The adhesion of 1,3,5-tri(4'-cyano-[1,1'-biphenyl]-4-yl)benzene (TCB) and 1,4-bis(4-cyanophenyl)-2,5-bis(decyloxy)benzene (CDB) molecules to step edges on the KCl(001) surface and the formation of molecular dimers were studied using classical molecular dynamics. Both molecules contain the same anchoring groups and benzene ring structures, yet differ in their flexibility. Therefore, the entropic contributions to their free energy differ, which affects surface processes. Using potential of mean force and thermodynamic integration techniques, free energy profiles and entropy changes were calculated for step adhesion and dimer formation of these molecules. However, converging these calculations is nontrivial and comes at large computational cost. We illustrate the difficulties as well as the possibilities of applying these methods towards understanding dynamic processes of organic molecules on insulating substrates.

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