Towards graphene-based devices: Fabrication and characterization
Licentiatavhandling, 2012

Graphene is a new material with a large set of impressive properties, interesting both for fundamental studies and applications. Reliable synthesis of large-scale, high-quality graphene is key to its future success. This thesis is focused on the development of such fabrication techniques and experimental studies on three different graphene-based devices. The highest quality graphene is produced by mechanical exfoliation of graphite. While this technique is not scalable, it provides high quality graphene for scientific purposes and proof of principle devices. Catalytic chemical vapor deposition of graphene on copper is the most promising scalable method for graphene synthesis. Techniques for high temperature growth of graphene from methane as a precursor gas on high-purity copper foils are developed. Also, techniques for transferring the as‑grown graphene to insulating substrates are presented. Large-scale graphene with high uniformity and a mobility ~3000 cm2/Vs at room temperature is obtained. The transfer process needed for catalytically grown graphene on copper introduces issues with process reliability and future integration in semiconductor manufacturing. A non-catalytic chemical vapor deposition technique is shown to give uniform large-area graphene directly on insulating substrates like SiO2 and Si3N4, avoiding transfer. Raman spectroscopy, transmission electron microscopy, and transport measurements show that graphene grown this way is nanocrystalline and its electronic properties are inferior to those of catalytically grown graphene. Contamination and unintentional doping are difficult to avoid in graphene processing. A mechanical cleaning technique using an atomic force microscope is shown to efficiently remove contaminants and improve the electronic properties of graphene. The technique is easy and can be applied to substrates that cannot sustain standard graphene cleaning procedures. Graphene devices are realized on ferroelectric barium strontium titanate. The strong field effect in graphene is utilized as a read-out of the ferroelectric state, thus realizing a hybrid graphene-ferroelectric memory device. A graphene-based cold-electron bolometer is fabricated and characterized at cryogenic temperature. The low volume of graphene makes it an interesting absorber material for high-sensitivity bolometers. The Aharonov-Bohm effect is studied in graphene rings having metallic mirrors. The mirrors confine electrons to the Aharonov-Bohm ring, improving the visibility of higher-order Aharonov-Bohm oscillations.

Synthesis

Chemical vapor deposition

Mechanical cleaning

Aharonov-Bohm effect

Graphene

Ferroelectric

Bolometer

Kollektorn, MC2
Opponent: Dinko Chakarov

Författare

Niclas Lindvall

Chalmers, Mikroteknologi och nanovetenskap (MC2), Kvantkomponentfysik

Noncatalytic chemical vapor deposition of graphene on high-temperature substrates for transparent electrodes

Applied Physics Letters,; Vol. 100(2012)

Artikel i vetenskaplig tidskrift

Controllable chemical vapor deposition of large area uniform nanocrystalline graphene directly on silicon dioxide

Journal of Applied Physics,; Vol. 111(2012)

Artikel i vetenskaplig tidskrift

Cleaning graphene using atomic force microscope

Journal of Applied Physics,; Vol. 111(2012)p. Article Number: 064904-

Artikel i vetenskaplig tidskrift

Chemical vapor deposition of nanocrystalline graphene directly on arbitrary high-temperature insulating substrates

7th IEEE International Conference on Nano/Micro Engineered and Molecular Systems. NEMS 2012, Kyoto, 5 - 8 March 2012,; (2012)p. 11-14

Paper i proceeding

Family of graphene-based superconducting devices

JETP Letters,; Vol. 94(2011)p. 329-332

Artikel i vetenskaplig tidskrift

Low Partial Pressure Chemical Vapor Deposition of Graphene on Copper

IEEE Transactions on Nanotechnology,; Vol. 11(2012)p. 255-260

Artikel i vetenskaplig tidskrift

Large-area uniform graphene-like thin films grown by chemical vapor deposition directly on silicon nitride

Applied Physics Letters,; Vol. 98(2011)

Artikel i vetenskaplig tidskrift

Styrkeområden

Nanovetenskap och nanoteknik

Infrastruktur

Nanotekniklaboratoriet

Ämneskategorier

Den kondenserade materiens fysik

Technical report MC2 - Department of Microtechnology and Nanoscience, Chalmers University of Technology: 1652

Kollektorn, MC2

Opponent: Dinko Chakarov

Mer information

Skapat

2017-10-07