Effect of loading and standbye time of the organic dye N719 on the photovoltaic performance of ZnO based DSSC

In this work, ZnO nanopowders were synthesized by microwave assisted hydrothermal method. To measure the photoelectrochemical properties of the obtained ZnO nanopowders, ZnO film was coated on FTO by using doctor blade method and the dye solution consisting N719 was used. For the investigations of structural and morphological properties, X-ray diffraction (XRD) measurements and scanning electron microscopy (SEM) analysis were carried out. The optical reflectance of the ZnO films with and without dye were recorded using spectrophotometer and by using Kubelka-Munk function, the two optical band gaps were detected at about 3.25 eV (direct band gap of ZnO) and 2.20 eV. The current-voltage (I-V) characterizations of fabricated ZnO-DSSCs were performed for three consecutive days and the best performance was obtained from the cell at 2 h loading time and 2 day standbye time, with their photovoltaic parameters were the J(sc) of 1.62 mAcm(-2), V-oc of 0.64 V, FF of 0.62, and n% of 0.64%, respectively. (C) 2019 Elsevier B.V. All rights reserved.