Experimental investigation on the structural, dielectric, ferroelectric and piezoelectric properties of La doped ZnO nanoparticles and their application in dye-sensitized solar cells

Abstract

Pure and lanthanum (La) doped ZnO nanorods were synthesized via co-precipitation method. The structure and morphology of as grown ZnO and La-ZnO nanoparticles were studied using transmission electron microscopy (TEM) and powder X-ray diffraction (XRD) methods. The values of remnant polarization and coercive field were found to be 0.027μC/cm2 and 1.33kV/cm, respectively, for as grown La-ZnO nanostructures. High Curie temperature (276°C) for doped ZnO was observed in dielectric study. Piezoelectric coefficient at room temperature was found to be 101.30pm/V. I-V characteristics were studied for both pure and doped ZnO nanoparticles. Photo-anodes of dye-sensitized solar cells (DSSCs) were made using ZnO and La-ZnO nanorods. The conversion efficiency and short circuit current density of La-ZnO nanorods based DSSC were 0.36% and 1.31mA/cm2, respectively, which were found to be largely enhanced when compared with that of pure ZnO based DSSC (0.20% and 0.94mA/cm2).