G5 Doctoral dissertation (article)
Modification of graphene properties by optical forging (2021)

Hiltunen, V.-M. (2021). Modification of graphene properties by optical forging [Doctoral dissertation]. Jyväskylän yliopisto. JYU Dissertations, 362. http://urn.fi/URN:ISBN:978-951-39-8560-8

JYU authors or editors

Publication details

All authors or editors: Hiltunen, Vesa-Matti

eISBN: 978-951-39-8560-8

Journal or series: JYU Dissertations

eISSN: 2489-9003

Publication year: 2021

Number in series: 362

Number of pages in the book: 1 verkkoaineisto (93 sivua, 51 sivua useina numerointijaksoina, 29 numeroimatonta sivua)

Publisher: Jyväskylän yliopisto

Place of Publication: Jyväskylä

Publication country: Finland

Publication language: English

Persistent website address: http://urn.fi/URN:ISBN:978-951-39-8560-8

Publication open access: Openly available

Publication channel open access: Open Access channel

Abstract

Graphene is one atom layer thin carbon material that has gained plenty of attention due to its numerous excellent properties. In this thesis a novel method to modify the structure and properties of graphene, called optical forging, is presented. In this method graphene is irradiated using femtosecond pulsed laser light and as a result of it graphene forms three-dimensional structures. Detailed characterizations have revealed that the process of optical forging causes defects to the graphene lattice, which in turn causes lattice expansion and bulging of graphene into the 3D shapes. In addition to this, some amorphous carbon is deposited onto graphene as a side effect, and the formation of the entire 3D shape is a combination of both bulging and deposition. Using nanoindentation measurements, optically forged graphene was determined to have high bending stiffness, which is very different from pristine graphene, which is very flexible. Optically forged patterns are also and more reflective than pristine graphene and they exhibit photoluminescence. As for applications, optical forging can be used to make ultralight scaffold structures from graphene, and potentially to increase the resonance frequencies of graphene resonator devices.

Keywords: graphene; thin films; nanostructures; chemical vapour deposition; three-dimensionality; manufacturing; laser pulses; optical properties; physical properties; doctoral dissertations

Free keywords: graphene; nanoindentation; graphene quantum dot; chemical vapor deposition; Raman spectroscopy; atomic force microscopy; elastic modulus; defect engineering; optical forging

Contributing organizations

Ministry reporting: Yes

Reporting Year: 2021