Optimization of MoO3 buffer layer thickness for short circuit current enhancement in Ag nanoparticle incorporated CuPc solar cell

Metal nano-particles (MNP) have been used for light trapping in the photovoltaic material. Concerns about the excitons generated being quenched by the MNP exist. Thus organic bilayer solar cells have to be designed with a buffer layer between the MNP and the active layers. In the device structure used in this study, silver MNP were thermally evaporated over indium tin oxide coated glass substrate. A layer of molybdenum oxide (MoO3) was deposited on the MNP before depositing the copper-phthalocyanine (CuPc) active layer. The thickness of MoO3 layer was varied to study its optical and electrical effects on the layer-stack. The spectral response of the different layer stacks with aluminum electrodes deposited on CuPc helped quantify and compare the improvement in short circuit current possible due to the absorption enhancements. Simulation has been carried out using finite element method to study role of near field and plasmonic scattering due to the MNP. The thickness range of MoO3 that would maximize the short circuit current has been identified.