Implications of relaxation dynamics of collapsed conjugated polymeric nanoparticles for light-harvesting applications.

Conjugated polymer-based nanostructures have been explored extensively from energy harvesting to healthcare applications due to their unique photophysical properties. This perspective includes the mechanism of the formation of polymer nanoparticles from linear chain polymers by utilizing experimental and theoretical studies. Conjugated polymer nanoparticles lead to changes in excitonic absorption bands, photoluminescence (PL) bands, and relaxation kinetics due to the inter-chain interactions between the chromophoric sub-units and the formation of the low-lying delocalized collective state. Here, we have illustrated the current understanding of the ultrafast relaxation dynamics of π-conjugated polymer-based nanostructured materials using global and target analysis. We have shown the impacts of the photoinduced carrier dynamics of polymer nanoparticles on the energy and charge transfer processes. Polymer nanoparticles found promising applications in bio-imaging, photothermal and photodynamic therapeutic agents, photocatalysis, and lasing materials. Finally, we have given the future perspectives of luminescent polymer nanoparticles.