الفهرس | Only 14 pages are availabe for public view |
Abstract Organic semiconductors (OSCs) are gaining attention due to their processability, optical and electrical tunability, and cost-effectiveness. This class of materials is most suitable for flexible electronics and bioelectronics, especially when processed in a solution with inorganic or hybrid materials. However, the charge mobility within these materials is impeded by structural and energetic disorder caused by defects that trap the charge carriers. The physical locations of the traps and their distribution of energies dictate the charge transport in a device. The present work probes the impact of incorporated various concentrations of both copper oxide (CuO) and nickel oxide (NiO) nanoparticles (NPs) blended with poly 3-hexylthiophene: [6, 6]-phenyl-C61-butyric methyl ester (P3HT: PCBM) bulk-heterojunction devices. The devices were studied using steady-state current-voltage (J-V) characteristics, UV-visible absorption spectrum, external quantum efficiency (EQE), X-ray diffraction (XRD), scanning electron microscope (SEM) and atomic force microscopy (AFM). In addition, the defect states from the nanoparticles and their effect on charge mobilities were studied using charge extraction by linearly increasing voltage (CELIV) technique. With an optimum concentration of metal oxides nanoparticles in P3HT: PCBM the power conversion efficiency (PCE) was improved compared to devices without these nanostructured particles. The overall improvement in the photovoltaic properties of the devices 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 the optimum concentration of these nanoparticles, the device’s performance deteriorated from high trapped charge density as monitored by the steady-state I-V characteristics and CELIV technique. |