Initial dynamic thermal dissipation modes enhance heat dissipation in gold nanoparticle–polydimethylsiloxane thin films

Plasmonic nanocomposite materials have exhibited value for applications ranging from biological hyperthermia to optical sensing and waveguiding. Energy absorbed from incident irradiation can be re-emitted as light or decay into phonons that propagate through the surrounding material and increase its temperature. Previous works have examined steady-state thermal dissipation resulting from irradiated plasmonic nanocomposites. This work shows heat dissipation in the first few seconds can significantly exceed that during subsequent steady state, depending on film geometry, nanoparticle diameter and concentration, laser irradiation power, and position within and adjacent to the irradiated spot. Films of lower thickness containing 16 nm gold nanoparticles (AuNPs) irradiated at 13.5 mW laser power showed highest enhancement and tunability of the dynamic thermal mode within and adjacent to the irradiated spot. Measured initial nanocomposite film temperature in or near the irradiated spot exceeded that resulting from constant bulk film thermal dissipation. These results improve understanding of cooling dynamics of resonantly irradiated nanocomposite materials and guide development of devices with enhanced thermal dissipation dynamics.