Thermoplasmonic Dissipation in Gold Nanoparticle-Polyvinylpyrrolidone Thin Films

Thermal dissipation of plasmon energy from gold nanoparticles (AuNPs) dispersed in transparent polymers is important to biotherapeutics, optoelectronics, and sensing. This work evaluated heat dissipated by 16 nm AuNPs with negligible Rayleigh scattering cross-sections dispersed into sub-wavelength, 70-nm polyvinylpyrrolidone (PVP) films at interparticle spacings much less than the resonant wavelength. Compared to super-wavelength films with interparticle spacing near the resonant wavelength, measured optical extinction and temperature increase on a per NP basis decreased as AuNP concentration increased; change in temperature per NP decreased 22% and optical extinction per NP decreased 35% as AuNP concentration increased from 1.01 to 5.06 x 10¹⁵ NP/cm³. The trend and magnitude of measured values were consistent with those from a priori description of optical extinction per NP derived from Maxwell Garnett effective medium theory (EMT) and from coupled diode approximation (CDA). Comparison of EMT, CDA, and finite-element analysis measured results showed the contributions to plasmon-resonant optical extinction and heat dissipation. These results support design and adaptive control of thermal dissipation from plasmonic films.