Luminescence, patterned metallic regions, and photon-mediated electronic changes in single-sided fluorinated graphene...

Area of Science:

• Materials Science
• Condensed Matter Physics
• Surface Science

Background:

• Single-sided fluorination of graphene was theoretically predicted to create an electronic band gap and unique properties.
• Experimental validation of these predictions for fluorographene has been lacking.

Purpose of the Study:

• To experimentally investigate the electronic and structural properties of single-sided fluorographene.
• To characterize the different phases of fluorographene and their transitions.
• To explore the potential for patterning this 2D material.

Main Methods:

• Experimental synthesis and characterization of single-sided fluorographene on a SiC(0001) substrate.
• Theoretical calculations to support experimental findings.
• UV irradiation and annealing to induce and study phase transitions.
• X-ray magnetic circular dichroism (XMCD) to probe magnetic properties.

Main Results:

• Two distinct phases of single-sided fluorographene were identified: a stable phase with a ~6 eV band gap and a metastable phase with a ~2.5 eV band gap.
• The metastable phase is induced by UV irradiation and reverts to the stable phase upon annealing, emitting blue light.
• Structural analysis revealed a
• boat
• structure for the stable C2F phase, and XMCD data indicated the absence of an ordered magnetic phase.
• High-energy photons (UV or X-ray) were shown to remove fluorine atoms, enabling patterning.

Conclusions:

• Single-sided fluorographene exhibits tunable electronic properties through phase transitions.
• The metastable phase is likely stabilized by defect states.
• Fluorographene is not magnetically ordered in its stable phase.
• Photonic patterning offers a route to create conducting regions in this semiconducting 2D material.