Synthesis of Fulleride Thin Films with Ultra-low Thermal Conductivity.

Abstract

ABSTRACT:In the past two decades, there has been growing interests in the design and improvement of thermoelectric (TE) materials and devices largely due to their potential use in technologies such as: 1) the conversion of waste heat to electricity, 2) solid-state refrigeration and heating, 3) biomedical batteries, and 4) power sources for both ground and space-based electronics.1 Recent research has suggested that by using nanotechnology (i.e. nanostructuring / nanoengineering) large advances can be gained in controlling interfaces to hinder thermal transport while allowing electrical movement. Thin film structuring of thermoelectric materials potentially offers several advantages over bulk thermoelectric materials especially for cooling applications. Furthermore, others have advocated that by making thermoelectric materials very small, one can achieve an enhanced ZT (the thermoelectric figure of merit) due to quantum confinement effects.2-5 The structure and physical properties of doped fullerene materials were investigated for use as electrically conducting phonon blocking layers. The synthesis and thermal properties of ZnxC60 thin films are reported. Preliminary results have shown the formation of amorphous fullerides structures with thermal conductivities as low as 0.13 Wm-1K-1. Physical and structural measurements (e.g. Electron Microscopy, Electron Diffraction, and Raman Spectroscopy) will be reported detailing the unique structure-property relationships in these materials.