Plasmonic–Diamond Hybrids: Tunable Optical and Thermal Response for Nanoscale Applications

Hybrid metal–diamond nanostructures unlock new opportunities for precision plasmonics and nanoscale thermal control. Here, we employ frequency domain finite‐element simulations to elucidate the optical and thermoplasmonic behavior of gold and silver nanoparticle clusters integrated with a nanodiamond core. By systematically varying interparticle spacing, cluster size, core conductivity, and dielectric environment, we reveal how nanodiamond incorporation reshapes near‐field coupling, amplifies absorption, and modulates resonance shifts. Conductive cores deliver stronger plasmon hybridization and enhanced photothermal response, while refractive‐index tuning induces pronounced spectral redshifts, particularly in silver clusters with sharp multipolar resonances. Coupling plasmonic with thermal modeling uncovers the role of nanodiamond as a nanoscale heating enhancer. These insights establish design principles for plasmonic–diamond architectures, enabling high‐sensitivity sensing, controlled nanoheating, and integrated photonic platforms.