Scanning thermal microscopy of carbon nanotube electronic devices

Scanning probe microscopy techniques including scanning gate microscopy (SGM) and scanning thermal microscopy (SThM) have been used to investigate electron transport and energy dissipation mechanisms in single-walled carbon nanotube (CNT) electronic devices. An ultra thin (5-10 nm) layer of polystyrene was coated on the device to protect the CNT devices during thermal imaging. A first harmonic ac measurement SThM method has been developed to improve the signal-noise ratio. Our recent results reveal diffusive and dissipative charge transport in a semiconducting single-walled CNT at applied bias as low as 0.1 V. We have also observed uniform heat dissipation in a metallic single-walled carbon nanotube at applied biases above 0.4 V.