Copper oxide nanoparticle doped bulk-heterojunction photovoltaic devices

Organic and metal oxide-based hybrid solar cells have drawn attention for their improved device performance along with mechanical stability and cost-effectiveness. We investigated the incorporation of various concentrations of copper oxide (CuO) nanoparticles (NPs) blended with poly 3-hexylthiophene: [6,6]-phenyl-C-61-butyric methyl ester (P3HT:PCBM) bulk-heterojunction devices. With an optimum concentration of CuO NPs in P3HT: PCBM the devices power conversion efficiency is about 35% larger than without CuO NPs. The overall improvement in the photovoltaic properties of the device is attributed to the improved optical absorption, crystallinity and roughness of the photoactive layer confirmed by the AFM and XRD characteristics of the blended films. Beyond optimum nanoparticle concentration deteriorates the device performance from high trapped charge density as evidenced by steady-state current-voltage characteristics and charge-extraction-by-linearly-increasing-voltage (CELIV).