Hybrid solar cells using monodisperse Cu 2 S nanodisks compositing with the mixture of poly (3-hexylthiophene):1-(3-methoxycarbonyl) propyl-1-pheny [6,6] C61 (P3HT:PC 60 BM) as the active layer have been fabricated and characterized. The hybrid solar cells exhibit the highest efficiency of 1.35% when the weight ratio of P3HT:PC 60 BM:Cu 2 S is 1:0.8:0.224. The power conversion efficiency (PCE) of nanocomposite device is increased 22.7% comparing with that of the device based on pure P3HT/PC 60 BM. It is due to that the effect of high-quality Cu 2 S nanodisks with good dispersity contributes the increased electronic transportation in the active layer and results in the enhancement in photovoltaic performance. We also investigated the morphology of photoactive layer by microscope; it is found that the dispersity of nanomaterial in active layer is very important for device performance and improvement of carrier mobility.