Enhancement of light-emitting efficiency using combined plasmonic Ag grating and dielectric grating

► Using combined plasmonic Ag and dielectric gratings. ► Plasmonic Ag grating enhances the near-field evanescent wave. ► Hybrid Ag and dielectric gratings couple the evanescent wave to propagation wave. ► Enhancement factor of the light extraction efficiency can reach 4 times at a relatively longer wavelength.