High repetition rate femtosecond laser irradiation: mechanisms and applications

• Main Author: KHON, CHO
• Other Authors: Tay Beng Kang
• Format: Final Year Project
• Language: English
• Published: 2016
• Subjects: DRNTU::Engineering
• Online Access: http://hdl.handle.net/10356/68040
• Institution: Nanyang Technological University

Graphene under high voltage bias produces a wealth of phenomena due to high temperatures reached via joule heating. Electrical breakdown at high current density in order of 108 A/cm2 and formation of nanometer sized gap/crack via carbon sublimation was reported in recent studies. In this project, we develop a method to control the formation and propagation of this nanometer sized gap. Using high repetition rate (80MHz) USP Femtosecond infrared laser, defects smaller than 2µm are introduced into two terminal Graphene resistors. Subsequent electrical stress shows that the rupture of Graphene propagates along the path of defects. Fabrication of nanometer sized gaps with precise control is desirable in order to use Graphene as electrodes in molecular electronics. Our findings provide simple and highly reproducible method to structure Graphene in nanometer scale, compared to existing methods such as e-beam or AFM lithography process.