Stress and thermal characterization of bent graphene using THz na-noscopy

You will use THz nanoimaging techniques to investigate the properties of graphene in various condi-tions in the THz regime.

The THz regime is the bridge between optics and electronics. THz radiation is non-ionizing and non-invasive and can be used for various applications, especially for imaging. However, the THz wavelength is between 3 mm and 30 um, so it is challenging for nano-scale imaging. In this work, you will use an in-house-built THz scanning near-field microscope (THz-sSNOM) to characterize graphene under stress and at different temperatures. While graphene has been studied mainly on flat surfaces, graphene has not yet been studied under stress and at changing temperatures, conditions that graphene undergoes while it is used in devices such as THz detectors. During this project, you will characterize graphene un-der various conditions and compare the physical properties in the THz regime. Moreover,  you will use techniques such as 3D printing to build components supporting the experimental work.

We are looking for motivated students with a physics, material science, electrical engineering, or chem-istry background for an MSc thesis in the Transport at Nanoscale Interfaces Laboratory at Empa.

During the project, the MSc student will work on the following:

  • Nanoimaging with THz-sSNOM
  • 3D printing
  • Raman Spectroscopy
  • Matlab/python for data analysis

Figure 1. Blender illustration of THz-sSNOM.

Goal
Study graphene under stress and heat and characterize its properties for future development of flexible THz devices.
Relevant references for the project:
  • Maissen et al., Probes for Ultrasensitive THz Nanoscopy, ACS Photonics 2019, 6, 5, 1279–1288
  • Zhang et al., Terahertz Nanoimaging of Graphene, ACS Photonics 2018, 5, 7, 2645–2651