Atomic-scale imaging of insulating diamond through resonant electron injection

Area of Science:

• Materials Science
• Surface Science
• Condensed Matter Physics

Background:

• Insulators like diamond possess unique electronic properties crucial for electronics.
• Investigating insulator surfaces at the atomic scale is challenging due to their lack of conductivity.
• Conventional techniques like scanning tunneling microscopy (STM) are typically unsuitable for insulating materials.

Purpose of the Study:

• To develop and demonstrate a novel STM method for imaging and probing the electronic properties of insulating diamond surfaces at the atomic scale.
• To overcome the limitations of existing characterization techniques for non-conductive materials.

Main Methods:

• Utilized an unconventional resonant electron injection mode with scanning tunneling microscopy (STM).
• Applied the technique to high-purity diamond single crystals.
• Enabled atomic-scale imaging and electronic property investigation of insulating surfaces.

Main Results:

• Successfully imaged insulating diamond surfaces using STM.
• Revealed striking electronic features, including one-dimensional fully delocalized electronic states.
• Measured a very long diffusion length for conduction-band electrons in diamond.

Conclusions:

• The developed resonant electron injection STM method is effective for characterizing insulating materials.
• This technique opens new avenues for studying the electronic properties of insulators at the atomic scale.
• The findings facilitate the design of novel atomic-scale electronic devices utilizing insulating materials.