NER: Exploring Thermoelectric Energy Conversion in Nanostructure Assemblies

Rensselaer Polytechnic Institute, Troy NY

Investigators

Abstract

NER: Exploring Thermoelectric Energy Conversion in Nanostructured Assemblies The objectives of this project are: (1) the enhancement of the thermoelectric figure of merit using a new concept of nanostructured materials, and (2) the development of strategies for fabrication and testing of low-dimensional thermoelectric energy-conversion devices. The influence of zero-dimensional nanostructures on the thermoelectric figure of merit in nanocluster assemblies grown by a versatile technique applicable to a wide variety of material systems and configurations is studied. The nanoclustered assemblies are 0-D systems based on monodisperse elemental and compound nanoclusters between 1-10 nm in size capped with self-assembled monolayers (SAMs) and assembled in layered configurations using SAMs of different lengths and functionalities. The enhanced quantum confinement and the acoustic mismatch effects between the nanoclusters and the molecular connectors are employed to maximize the thermoelectric figure of merit. To address the second objective, thermoelectric energy-conversion devices are fabricated comprised of junctions between dissimilar nanostructured materials. Planar junctions are formed between films of p-type and n-type nanocluster assemblies. Junctions are formed between carbon nanotubes and metal nanowires using a recently devised selective nanotube growth process. Alternatively, alumina templates and metal electrodeposition are used to create these junctions. Scanning probe and electrical self-heating and thermometry techniquesare developed and used to assess the Peltier effect of the fabricated junctions. Broader Impact: This multidisciplinary approach leads to an understanding of key aspects of dimensional confinement that impact thermoelectric properties, and paves the way for use of nanoclusters in this area. The project will also provides fabrication and testing strategies for future nanoscale energy-conversion devices. CNT-metal hetero-junctions could be employed as nanoscale temperature/radiation sensors and nano-heat pumps, presenting a whole new range of applications for carbon-nanotube-based devices and electronics. The project actively involves undergraduate researchers funded through a NSF-REU summer program and the Rensselaer URP program