Influence of Au nanoclusters on the Power Conversion Efficiency of Hybrid Solar Cells

Recently, organic/inorganic hybrid solar cells have been extensively studied as a means to fabricate low-cost, relatively high efficiency solar cell devices. Along this line of research, we report the observed enhancement in the power conversion efficiency of poly(3,4-ethylenedioxythiophene): poly(styrene sulfonate) (PEDOT:PSS) on planar silicon (Si) hybrid heterojunction solar cell devices when incorporating gold (Au) nanoclusters in the PEDOT:PSS blend. The Au nanoclusters of size 3-5 nm were synthesized by wet chemical methods, and capped with 4-mercaptobenzoic acid (p-MBA). The power conversion efficiency (PCE) of the described structures with Au nanoclusters was measured to be 8.2%, which compares well to the PCE value of 7.3% for similar devices without the nanoclusters. The increased PCE of the devices is attributed to the measured increased electrical conductivity as well as near field plasmonic effects of the aforementioned films due to the incorporation of the Au nanoclusters, which is directly reflected in the improved fill factor and external quantum efficiency (EQE) of the devices produced.