Broadband Scattering With Strong Electric Field Coupling Between Metal Nanostructures Using DDA Simulation: Role of Different Organic Environments

A numerical model to study the optical properties of silver and gold nanoparticles surrounded by various organic media using a discrete dipole approximation method has been considered. The overall extinction and scattering (including forward and backward) efficiency with respect to wavelength has been analyzed to obtain optimized parameters for metal nanoparticles (MNPs) embedded in different organic matrices. P3HT:PCBM blend (Poly (3-hexyl thiophene))-(phenyl-C61-buryricacid methyl ester), P3HT (poly (3-hexyl thiophene)), and PEOPT (1”, 4”, 7”-trioaoctyl) phenyl) theophany) are taken as organic media in present calculation, where the Ag and Au nanoparticles of different sizes are embedded in it. MNPs support surface plasmon resonance having a wide range of tunability in the wavelength domain 300–700 nm. The tunability of surface plasmon resonances is highly sensitive to the particle size, as well as surrounding media. The numerical model is simulated for the spherical-shaped MNP of size 10–160 nm. The analysis of electric field intensity has been done for selective sizes of MNP. The magnitude of field intensity is highly sensitive to parameters associated with the metal structure and surrounding media. The entire numerical experiment has been replicated for the multiparticle system, in which the interaction between the nanoparticles has been considered. This gives an extra degree of freedom and wide tunability. Overall results are very encouraging and show better photon absorption in P3HT:PCBM blend for the 300–700-nm spectral range, as well as enhanced overall performance, as shown by the J–V curve.