NER: One-Dimensional Nanoparticle Composites for Thermoelectric Applications

University Of New Orleans, New Orleans LA

Investigators

Abstract

This proposal was received in response to the Nanoscale Science and Engineering initiative, NSF 04-043, category NER. The objective of this research is to develop high-performance materials for thermoelectric applications. Thermoelectric devices are currently used for solid-state cooling and the direct conversion of thermal to electrical power. The applications of these devices are limited, however, by their low efficiency. This project will develop composite materials consisting of a chain of nanometer-sized semiconducting particles (nanoparticles) linked by a conducting polymer. This material architecture will take advantage of the enhanced electrical properties of nanometer-scale semiconducting materials combined with the low thermal conductivity of the polymer. This combination of properties is expected to provide measurable improvements over today's thermoelectric materials. The approach is to chemically synthesize nanoparticles, mix them with specific organic molecules (monomers) and electrochemically polymerize the monomer inside nanometer-sized channels of a ceramic template. The electrical and thermal properties of the composite will be measured, analyzed and evaluated. The most significant challenge is creating a suitable electrical connection between the polymer and semiconducting particle. This will be addressed by chemically coating the particles with organic molecules which attach to the particle's surface on one end of the molecule and electrically link to the polymer on the other. The outcome of this project will impact both solid-state cooling and power generation technologies. Enhancements in thermoelectric materials would enable devices which could efficiently convert thermal to electrical power using waste heat or using the normal temperature differences of the environment (so-called "energy harvesting" applications). A large enough enhancement (~ factor of 4 over existing materials) would give thermoelectrics a competitive advantage in air conditioning and refrigeration. It might also make feasible cryogenic electronics and computing, providing new opportunities for electronic devices based on superconductivity and other low temperature phenomena.