Surface-plasmons enhanced light emitter based on Ag film in GaN

We study the contribution of Surface-plasmons coupling with a single dipole to enhance the emitter emission. When the Ag film is inserted into GaN, the emission efficiency of single dipole in GaN can be enhanced greatly. With 3D-FDTD method, the numerical simulation results demonstrate that the SPs play a key role in enhancement light emitter efficiency. Furthermore, SPs is sensitive not only to the thickness and refractive index of dielectric, but also to the geometry and dispersion model of Ag film. By changing the parameters of GaN and Ag film, the location of the enhancement peak of the emission efficiency in the visible region can be controlled. According to the simply optimal parameters, about 9 times enhancement at 470nm occurs. Our results are of very importance for improving the light-emitting devices of GaN.