Efficient organic solar cells based on PTB7/PC71 BM blend film with embedded different shapes silver nanoparticles into PEDOT:PSS as hole transporting layers

In this study, two size-controllable silver nanoparticles, decahedral and icosahedron Ag NPs, were embedded into PEDOT:PSS as hybrid hole transporting layer (HTLs) for organic photovoltaic applications. The Ag-decahedral based nanoparticle exhibited rather red-shifted and larger domain size than Ag-icosahedron one. Due to the plasmonic and light harvesting effects of Ag NPs, the power conversion efficiency (PCE) was increased from 5.8% to 6.5 (decahedral-based) and 6.3% (icosahedron-based) in Poly[[4,8-bis[(2-ethylhexyl)oxy]benzo [1,2-b:4,5-b']dithiophene-2, 6-diyl] [3- fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3, 4-b] thiophenediyl]] (PTB7):[6,6]-Phenyl C71-butyric acid methyl ester (PC71BM) based-OPV upon embedding the Ag NPs. External quantum efficiency (EQE) enhancement was also observed due to the plasmonic scattering effect. The atomic force microscope (AFM) images showed the roughed results of the PEDOT:PSS/Ag NPs hybrid HTL films, i.e. better hole collection efficiency. Furthermore, the active layer did not show any aggregation and morphology change after adopting hybrid HTL films into the devices.