Thermal transport into graphene through nanoscopic contacts

Area of Science:

• Materials Science
• Nanotechnology
• Physics

Background:

• Graphene's exceptional thermal conductivity is key for advanced electronics.
• Its thermal properties are size-dependent, especially in the quasiballistic regime.
• Understanding heat transfer in few-layer graphene is crucial.

Purpose of the Study:

• To investigate graphene's thermal properties at the nanoscale.
• To quantify thermal resistance in individual atomic layers.
• To understand heat transfer mechanisms in few-layer graphene on different substrates.

Main Methods:

• High-resolution scanning thermal microscopy (SThM).
• Direct probing of local heat transfer.
• Measurements on amorphous silicon oxide (SiO2) and crystalline silicon carbide (SiC).

Main Results:

• Thickness-dependent thermal resistance modulations observed at sub-10-nm resolution.
• On SiO2, thermal resistance decreases with increasing graphene layers due to heat spreading.
• On SiC, thermal interface resistances dominate transport, limited by phonon mean free path.

Conclusions:

• Graphene's thermal conductivity is strongly influenced by layer number and substrate.
• Heat spreading effects are significant on SiO2.
• Thermal interface resistance is critical on SiC, impacting overall heat transport.