ZnO nanoparticles electron transport layer obtained by pulsed laser deposition for organic solar cells

Zinc oxide (ZnO) nanoparticles are commonly used as electron transport layer (ETL) material in organic solar cells (OSCs).The deposition of ZnO via Pulsed laser deposition (PLD) has attracted considerable attention currently due to its effect on the efficiency and stability of OSCs.In this work, ZnO powder was deposited by PLD using the (Nd: YAG) laser with constant power of 1000 mJ.ZnO was used as ETL in fabrication of organic solar cell with inverted structure (FTO/ZnO/PTB7-Th:O-IDTBR/MoO 3 /Ag).The electrical characterization and photo stability of the prepared OSCs has been investigated.The optical properties and structural characterization including the morphology and topography of ZnO film surface have been evaluated using field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM) and X-ray diffraction analysis (XRD).The results we obtained have shown that the power conversion efficiency (PCE) of the studied OSC exceeding 13 % under the continues illumination during 30 min decreased from 13.7 % to 1 % at the ambient air conditions.From the images of FESEM and AFM, the grains size of ZnO varied from 24-43 nm and this agree with XRD analysis.The cross section image showed that the films thickness was within the nanoscale.