Nanoscale Thermal Imaging of VO${}_2$ via Poole-Frenkel Conduction

Abstract

We present a method for nanoscale thermal imaging of insulating thin films using atomic force microscopy (AFM), and we demonstrate its utility on VO${}_2$. We sweep the applied voltage $V$ to a conducting AFM tip in contact mode and measure the local current $I$ through the film. By fitting the $IV$ curves to a Poole-Frenkel conduction model at low $V$, we calculate the local temperature with spatial resolution better than 50 nm using only fundamental constants and known film properties. Our thermometry technique enables local temperature measurement of \textit{any} insulating film dominated by the Poole-Frenkel conduction mechanism, and can be extended to insulators that display other conduction mechanisms.

References in corpus (3)

• Nanoscale thermal imaging of dissipation in quantum systems
• Electrostatic modification of infrared response in gated structures based on VO2
• Nanothermal Characterization of Amorphous and Crystalline Phases in Chalcogenide Thin Films with Scanning Thermal Microscopy