Strained graphene optoelectronic devices with unprecedented pseudo-magnetic fields

Abstract

Photonic-integrated circuit (PIC) is a research field that has been attracting many researchers’ interests owing to its great potential for enabling various disruptive technologies. In the past few decades, silicon-based PIC has been at the core of PIC development due to the maturity of industry-adopted silicon processing technologies. Since the first discovery of graphene in 2004, graphene-based PIC has been considered one of the strongest candidates to further improve the performance of silicon-based PIC for various reasons. For example, graphene has higher carrier mobility than silicon, which can allow making high-speed electronic devices. This property also enables producing very high-speed photodetectors. However, due to the zero-bandgap nature of graphene, it remains challenging to create a graphene-based light source, making the bandgap opening an important milestone for developing efficient graphene-based light sources. Recently, there have been several reports that theoretically predict the possibility of opening the energy gaps in graphene by using strain- induced pseudo-magnetic fields. In this Final Year Project (FYP) report, I investigate the research field of strained graphene particularly for harnessing pseudo-magnetic fields and pseudo-Landau levels. First, I present a review of several key papers discussing the strain- induced pseudo-magnetic fields. I then focus on discussing my research progress for monolayer graphene fabrication and the generation of strained graphene by using patterned substrates. Lastly, I discuss the characterization results of the fabricated devices using Raman spectroscopy.