Collecting Raman Spectrum from Monolayer Graphene
“FERGIE is a very compact system. The modular design makes it extremely convenient to use with microscopes, either by fiber or direct coupling.”
— Prof. Dr. Ping-Heng Tan, Institute of Semiconductors, Chinese Academy of Sciences
The research interest of Prof. Dr. Ping-Heng Tan at the Institute of Semiconductors, Chinese Academy of Sciences, focuses on the optical properties of two-dimensional layered materials and related heterostructures, nanocarbon materials, and novel low-dimensional semiconductor materials.
“Although small, FERGIE has good sensitivity. Raman spectra of graphene and silicon can be obtained by this smart system combined with a homemade micro-Raman module.”
See Figures 1 and 2.
FERGIE in Action
Figure 3 shows first and second order Raman spectra of graphene acquired via the homemade micro-Raman module with FERGIE system for confocal Raman spectroscopy. An He-Ne laser (632.8 nm, 10 mW) was used in the experiment.
Owing to its short focal length, FERGIE can yield very broad spectra in a single capture (>5000 cm-1, or >270 nm, with a 632.8 nm laser and a 600 g/mm grating), which is highly useful for both Raman and fluorescence experiments. See Figure 4.
Click images below to enlarge and see captions.
“The [LightField] software is quite easy to use. For example, you can choose a region of interest [ROI] on the CCD very quickly and accurately thanks to its imaging capabilities.”
Three Quick Questions
Princeton Instruments: How did the FERGIE system perform in your lab?
Ping-Heng Tan: FERGIE’s good sensitivity was confirmed by its ability to detect Raman spectra of the G and 2D modes of graphene using a 600 g/mm, 500 nm blazed grating via integration with a homemade micro-Raman module [as shown in Figure 3].
PI: How does FERGIE’s sensitivity compare to other spectrometers?
PHT: FERGIE provides a bridge between a professional Raman spectrometer and a handheld spectrometer. It can work at both a standard scientific lab and a field workstation.
PI: How will spectra acquired with FERGIE aid your research?
PHT: Due to its aberration-free performance, FERGIE can be used to detect photoluminescence signal in a very broad spectral range for each capture with high sensitivity. Meanwhile, it is sensitive enough to obtain Raman spectra of typical materials that distinguish the crystal structure.
Prof. Dr. Ping-Heng Tan
Institute of Semiconductors
Chinese Academy of Sciences