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Dye-sensitized solar cells (DSSCs) based on TiO2 and ZnO nanoparticles using low cost organic dye Coumarin 343 (C343), carbon counter electrode and iodide electrolyte were fabricated and compared. The two types of thin films were deposited on the transparent conducting oxide substrates by doctor Blade technique. The morphological and structural properties of these thin films were studied using SEM and XRD. Current-voltage measurements were carried out to investigate the DSSCs photovoltaic efficiency. The comparative performance study shows that the cell with ZnO/C343 as the photo-anode produces higher short circuit current density (Jsc) and open circuit voltage (Voc), which leads to higher energy conversion efficiency than the cell with TiO2/C343 as the photo-anode. UV-Visible and electrochemical impedance spectroscopy studies revealed the better performance of ZnO cell due to higher light absorption and slower electron recombination compared to TiO2 solar cell. [ABSTRACT FROM AUTHOR]

Zinc oxide (ZnO) is an n-type semiconductor with a large optical gap (3.4 eV) belonging to the transparent conductive oxides family (TCO). Strongly present as optical window in the chalcopyrite based structures CIGS and CIS. The structural, morphological, optical and electrical properties of ZnO thin films deposited onto glass substrates by ultrasonic spray pyrolysis (USP) technique have been investigated. For comparison and a better understanding of physical properties of undoped and (Al, In) doped ZnO thin films, a number of techniques, including XRD, SEM, optical absorption method (UV) and four-point probe technique were used to characterize the obtained ZnO thin films. Structural analysis shows that all the films were found to be polycrystalline with a wurtzite structure and show a (1 0 1) preferential growth. Besides, we noted that the preferred orientation does not depend on the nature of dopant. The band gaps (Eg) varied from 3.35 to 3.37 eV by Al and In dopants. [ABSTRACT FROM AUTHOR]