Study of external quantum efficiency of plasmonic coupled bilayer active device: influence of layer thickness and nanoparticle filling factor

To improve the efficiency of organic–inorganic photovoltaic devices, the inclusion of metal nanoparticles such as silver has been used to enhance photon absorption. Incorporation of silver nanoparticle into the active layer with various filling factor increases the exciton generation rate of active material. The exciton–plasmon coupling mechanism are analysed in terms of effective absorption coefficient via Maxwell Garnett theory including size effect. To obtain the exciton population of organic–inorganic heterojunction device with nanoparticle embedded into inorganic layer, we have solved one-dimensional steady-state exciton diffusion equation. On the basis of this, we have calculated the expression of photocurrent and external quantum efficiency with and without plasmonic effects under the influences of standard AM 1.5 solar spectrums. After embedding the silver nanoparticle (with filling factor 0.55) into inorganic active layer, optimum enhancement in the external quantum efficiency by 4.90% has been found as compared to reference device.