Wavelength-Dependent Tuning of Thermal and Thermoplasmonic Response in Aggregates of Porphyrins

The control of nanoscale thermally activated processes aided by plasmonic resonances has emerged as a cutting-edge research area in the plasmonic field with diverse applications spanning from medicine to material sciences. In this study, we present an optical and thermal analysis of a porphyrin aggregate using both finite element method simulations and an analytical/numerical approach based on full scattering theory. The simulated structure is a 3D right-handed helix, whose geometry reproduces an aggregate of porphyrins with lengths ranging from 22.5 to 150.0 nm. The investigation of the spectral regions of the H- and J-bands under illumination by a linearly polarized monochromatic plane wave shows that a consistent temperature rise is achieved by exciting the J-band, while heating is poor in the H-region. The geometry dependence of the electromagnetic field and temperature distributions is also investigated, proving a strong correlation between them.