Probing and Controlling Photothermal Heat Generation in Plasmonic Nanostructures

Vanderbilt University, Nashville TN

Investigators

Abstract

CBET-1336455 PI: Valentine The ability to model, control, and harness heat generation at the nanoscale is of fundamental and practical importance in areas ranging from chemical catalysis to medical therapy. This research project will investigate, both theoretically and experimentally, photothermal heat generation in metallic nanoscale optical antennae and nanostructures. Utilizing Babinet?s principle as a design framework, the researchers will investigate how conventional antennae exhibiting localized electric fields can be translated into novel thermal antennae exhibiting highly localized heat generation. These antennae will also be integrated with perfect absorber geometries in an effort to realize unity absorption and maximum local heat source density. Another key aspect of this project will be the development of a novel thermal microscopy technique which allows robust spatially resolved measurements of temperature and heat source density in nanoscale materials. This new microscopy method, deemed thermographic phosphor lifetime imaging microscopy, will be used to validate antenna designs and investigate the thermal response of complex nanostructures. The technique will be implemented in both a far-field and near-field configuration, allowing the characterization of global as well as nanoscale thermal transport phenomena in the antennae. Using these microscopy techniques, we will investigate nanoscale transport phenomena such as reduction in thermal / electrical conductivity and reduced melting temperature in the antennae to establish the maximum illumination power and failure mechanisms of the structures. This research will provide new insights into controlling and harnessing optically induced heat generation at the micro and nanoscale. This could lead to breakthroughs for a variety of devices and applications including photodetectors, chemical catalysis, thermally induced recording, and cancer ablation therapy. The development of an improved nanoscale thermal microscopy technique will also provide researchers in other fields a new tool to study thermal transport in micro and nanoscale materials with applications in areas such as thermoelectric energy conversion devices and microelectronic cooling. This research will also be integrated with science demonstrations to provide awareness, exposure, and excitement of science to K-12 students.