Imaging Dissipation and Hot Spots in Carbon Nanotube Network Transistors

TL;DR

This study employs infrared thermometry to visualize hot spots in carbon nanotube network transistors, revealing that junctions significantly influence heat dissipation and device reliability, with implications for improving CNN performance.

Contribution

It introduces a thermal analysis method to quantify junction thermal resistance in CNNs, highlighting the critical role of nanotube junctions in heat dissipation and device stability.

Findings

Identification of distinct hot spots during operation.

Average CNN temperature at breakdown is lower than individual nanotube breakdown temperature.

Junction thermal resistance is approximately 4.4x10^11 K/W.

Abstract

We use infrared thermometry of carbon nanotube network (CNN) transistors and find the formation of distinct hot spots during operation. However, the average CNN temperature at breakdown is significantly lower than expected from the breakdown of individual nanotubes, suggesting extremely high regions of power dissipation at the nanotube junctions. Statistical analysis and comparison with a thermal model allow the extraction of the average tube-tube junction thermal resistance, ~4.4x10^11 K/W (thermal conductance ~2.27 pW/K). This indicates that nanotube junctions have a much greater impact on CNN transport, dissipation, and reliability than extrinsic factors such as low substrate thermal conductivity.