Enhancement of the power conversion efficiency of organic photovoltaic cells due to Au@SiO2 core shell nanoparticles embedded into a WO3 hole transport layer

Organic photovoltaic (OPV) cells based on Au@SiO2-WO3 nanocomposites (NCs) embedded into a hole transport layer (HTL) were fabricated to enhance the power conversion efficiency (PCE) of those cells. The morphology of the Au@SiO2-WO3 NC film was uniform without any aggregation of the Au nanoparticles (NPs) resulting from the existence in the SiO2 shell of the Au@SiO2 NPs. With the optimized Au@SiO2 NP concentration of 5 wt%, the short-circuit current density and PCE of the OPV cells were enhanced by 125% and 31%, respectively, compared to the OPV cells containing WO3 NPs. The PCE enhancement of the OPV cells with a Au@SiO2-WO3 NC HTL originated from an increase in the short-circuit current density due to the enhanced the photon absorption resulting from the localized surface plasmon resonance effect and the enhanced hole extraction capability of the Au@SiO2-WO3 NC HTL.