I'm not sure what you mean. Do you want to visualise (in 3D) the fields calculated by FDTD that are inside your structure?
For 3D visualisation, I find that Paraview is useful software, and it is free. However, it is not always simple to import your data into it if your simulation software does not save in a suitable format.
LET me ask one question again, How can I form a device with different layers such as cathode (Al), buffer layer(PEDOT:PSS), Actives layer (P3HT:PCBM) and anode (ITO) and to embedded different size spherical shape plasmonic nanoparticle in Active layer with different thickness of active layer using FDTD to investigate the plasmonic resonance effect?