Plasmon-modulated photoluminescence mechanisms in plasmonic nanojunctions composites

Abstract

Plasmonic nanojunctions can generate hot electrons around them under irradiation, and these hot electrons can interact with the emissive materials around the plasmonic nanojunctions, resulting in a change in the photoluminescence mechanism of emissive materials. The emission enhancement factors of nanocomposites under plasmon-modulated effects strongly depended on (1) electron transfer mechanisms: direction and driving force of electron transfer between compositions; (2) the position and number of hot electrons generated around the dimer nanojunction. Under carefully controlled irradiation conditions (wavelength/intensity), these nanocomposites exhibit two different plasmon-modulated photoluminescence mechanisms: (1) suppression of photoluminescence: the emission enhancement factors of nanocomposites composed of conducting polymers can reach − 67%; (2) enhancement of photoluminescence: the emission enhancement factors of nanocomposites composed of emissive molecule (organic dyes) or emissive semiconductor crystal can reach 300% and 700%, respectively. These results paved the way for designing highly emissive composites for optically stimulated optoelectronic devices, solid-state lighting, biosensing et al.