Preparation of porous ZnO/MWCNT nanocomposite and ZnO nanoparticles derived from metal-organic framework and use them as photoanode in dye sensitized solar cell (DSSC)

In this research, Zn/MWCNT porous nanocomposite and ZnO nanoparticles were prepared using Zn-based metal organic framework (MOF). Porous ZnO without MOF precursor was also synthesized. Structure, morphology and size of the films were analyzed by XRD and scanning electron microscope (SEM). Dye sensitized solar cells (DSSCs) were fabricated with ZnO/MWCNT nanocomposite and ZnO nanoparticles as photoanode. It was determined that ZnO based on MOF show higher surface area, more photon absorption and better short circuit current density compared with the reference ZnO without MOF precursor. Moreover, Effect of multiwall carbon nanotubes (MWCNT) on the porous structure of ZnO was studied and DSSC based on ZnO/MWCNT photoanode exhibited a short circuit current density of 23.89 mA cm-2, open circuit voltage of 0.68 V, and power conversion efficiency of 4.78%, which is almost 15% larger than that of the DSSC based on ZnO photoanode based on MOF (4.06%). The enhancement of efficiency in DSSCs made of ZnO/MWCNT nanocomposite can be attributed to the increase of the electrical conductivity of the photoanode, strong connection between conduction band of the anode with dye molecules and more contact surface of photoanode with electrolyte.