A convenient method for large-scale STM mapping of freestanding atomically thin conductive membranes

Area of Science:

• Materials Science
• Nanotechnology
• Surface Science

Background:

• Atomically flat, flexible 2D materials like graphene are promising for ultrathin membranes.
• Microscopic investigation of these freestanding membranes presents significant challenges.

Purpose of the Study:

• To develop and demonstrate a method for large-scale mapping of freestanding graphene membranes using Scanning Tunneling Microscopy (STM).

Main Methods:

• Utilized ultra-high vacuum conditions with Scanning Tunneling Microscopy (STM).
• Employed unconventional STM parameters: very high tip-scan speeds, high feedback-loop gain, and low tunneling currents.
• Operated STM on several-micrometer-sized freestanding single and multilayer graphene membranes.

Main Results:

• Successfully achieved large-scale mapping of freestanding graphene membranes.
• Demonstrated the effectiveness of STM with specific, high-speed parameters for ultrathin membrane analysis.
• Observed unique membrane behavior distinct from solid substrates.

Conclusions:

• The developed STM method enables effective nanoscale investigation of flexible, freestanding graphene.
• This technique provides valuable insights into the properties of 2D materials in membrane form.
• The findings pave the way for advanced characterization of novel 2D materials.