[Seminar] Nanoscale thermal transport in organic materials
Résumé
With increasing degree of integration and downscaling of components, thermal management becomes one of the key parameters of improving performance and reliability of electronic devices, especially with the advent of 3D integrated circuits. Scanning Thermal Microscopy (SThM) is a known method for the characterization of local thermal conductivity of organic thin films. In this technique, the thin film resistor in the tip of scanning probe microscope is essentially utilized as a thermometer that allows obtaining decananometric lateral resolution.
Scanning probe microscopy in order to investigate the interplay between electrical and thermal transporting properties of PEDOT:OTf films on nanometric scale. C-AFM allowed us to measure electrical conductivity in out-of-plane direction and revealed significant (about 2 orders) anisotropy due to edge-on orientation of PEDOT chains on the substrate. Prior to our thermal measurements, we have validated the quantitative SThM on some samples of graphitized Kapton. Null-Point (NP) SThM was used for characterization of local thermal conductivity which demonstrated non-negligible electronic thermal transport in PEDOT:OTf. We modulated electrical conductivity of PEDOT:OTf thin films by employing different co-solvents during deposition as well as reducing agents for post-deposition treatment (de-doping). We measured out-of-plane thermal conductivity values for PEDOT:OTf samples with a wide range of electrical conductivities (0.04-140 S cm-1), for the purpose of estimating the electronic contribution to the thermal transport in this material.