Development of a nanostructure thermal property measurement platform compatible with a transmission electron microscope

Abstract

Measurements of the electrical and thermal transport properties of one-dimensional nanostructures (e.g., nanotubes and nanowires) typically are obtained without detailed knowledge of the specimen's atomicscale structure or defects. In an effort to address this deficiency, a microfabricated, chip-based characterization platform was developed, which enables both the observation of the atomic structure and measurements of the thermal transport properties of individual nanostructures. The measurement platform was designed for compatibility with a customized transmission electron microscope (TEM) specimen holder. An in-situ scanning electron microscope pick-and- place technique was developed to select and place an individual nanostructure onto the measurement platform. A through-hole for sample suspension and multiple electrical leads comprise the platform, permitting characterization of the individual specimen's atomic and/or defect structure, along with measurement of the specimen's thermal conductivity. This platform provides one with the unique ability to acquire structure-property correlations, such as the relationship between crystallinity, stacking faults, and dislocations to the sample's thermal transport properties. The work in this thesis details the development and fabrication of the measurement platform and further describes the development of a low-temperature measurement apparatus for performing temperature-dependent thermal conductivity measurements. Thermal conductivity measurements and TEM of individual GaN nanowires demonstrate the capabilities of the microfabricated platform.