Silver-nanoparticle-enhanced stimulated emission of organic thin films

To further reduce the lasing threshold of organic semiconductor materials, the surface plasmon resonance effect of silver nanoparticles was investigated. The prepared silver nanoparticle solution was spin-coated on glass substrate, and then PS:Alq3:DCJTB organic thin film was spin-coated on the surface of Ag nanoparticles, and thus formed a planar waveguide. Pumped by YAG (λ=355 nm) laser, the stimulated emission results show that compared with the case without Ag nanoparticles, the Ag-nanoparticle-enhanced edge stimulated emission increases 10.38-fold and its lasing threshold reduces to 0.5 mJ/cm² from 2.0 mJ/cm². The vertical surface stimulated emission increases 6.13-fold and its lasing threshold reduces to about 1.5 mJ/cm² from 2.5 mJ/cm². This work may be of great significance in the realization of low-threshold organic semiconductor lasers.