This technology relates to nanoparticles that are particularly beneficial in optical systems. The nanoparticles include phosphor-functionalized particles with an inorganic nanoparticle core, surface polymer brushes in the form of long and short-chain polymers bonded to the inorganic nanoparticle core, and organic phosphors bonded to the inorganic nanoparticle core or the short-chain polymers. Applications for this technology include LEDs, lighting devices, fixtures, efficient light conversion materials, etc.