Improved performance of solution processed organic solar cells with an additive layer of sol-gel synthesized ZnO/CuO core/shell nanoparticles

In this study, ZnO/CuO core/shell nanoparticles with ZnO:CuO molar ratios of 1:1M, 1:2M and 2:1M were successfully synthesized via sol-gel method. The synthesized nanoparticles were characterized to investigate for their morphology, structure, purity and optical properties. XRD analysis confirmed that the synthesized particles are in nanometer range with average particle size less than 100 nm and was further verified by TEM analysis. SEM images revealed spherical shape of nanoparticles. EDX analysis confirmed the purity of nanoparticles. Near band edge emission and broad green band was recorded in the PL spectra. The bandgap of synthesized nanoparticles was observed in the range 3.85-3.91 eV. Furthermore, the effect of adding an extra active layer of ZnO/CuO core/shell nanoparticles on the performance of organic solar cell with photo active layer electron donor poly (3-hexylthiophene-2,5-diyl) (P3HT) and electron acceptor [6,6]-phenyl-C-71-butyric acid methyl ester (PC71BM) was studied. Results showed that the added inorganic layer improved the absorption in visible region with increase in surface roughness of the active layer. The power conversion efficiency (PCE) shows improvement by inclusion of inorganic layer prior to organic active layer blend. This increase in PCE was basically due to increase in V-oc, J(sc) and FF of the fabricated device. (C) 2019 Elsevier B.V. All rights reserved.