Plasmon Enhanced Direct Bandgap Emissions in Cu₇ S₄ @Au₂ S@Au Nanorings

Nanostructured copper sulfides, promising earth-abundant p-type semiconductors, have found applications in a wide range of fields due to their versatility, tunable low bandgap, and environmental sustainability. The synthesis of hexagonal Cu₇ S₄ @Au₂ S@Au nanorings exhibiting plasmon enhanced emissions at the direct bandgap is reported. The synthesized Cu₇ S₄ @Au₂ S@Au nanorings show greatly enhanced absorption and emission by local plasmons compared to pure copper sulfide nanoparticles.