Structural, morphological, electrical and electron transport studies in ZnO–rGO (wt% = 0.01, 0.05 and 0.1) based dye-sensitized solar cell

Abstract

Zinc oxide–reduced graphene oxide (ZnO–rGO) thin films were fabricated on a fluorine-doped tin oxide glass substrate by a chemical bath deposition method. The thin films were immersed in the Eosin Y dye for 24 and 48 h to be fabricated as a dye-sensitized solar cell. ZnO hexagonal wurtzite structures were analyzed by X-ray diffraction analysis. Field effect scanning electron microscope showed the images of ZnO nanoparticles and nanobranches. The atomic force microscopy analysis estimated the average roughness of ZnO–rGO films doped with 0.01, 0.05 and 0.1 wt% which varied from 178 to 267 nm. The electrical or photovoltaic performance of ZnO–rGO were measured and compared accordingly by considering their power conversion efficiency, η, photocurrent density, Jsc, open-circuit voltage, Voc and fill factor, FF. The cell’s efficiency of ZnO with 0.01 wt% rGO, 0.05 wt% rGO and 0.1 wt% rGO reached η = 2.36, 0.78 and 0.38 %, respectively. EIS analysis estimated the effective electron lifetime, τeff, effective electron chemical diffusion coefficient, Deff, effective electron diffusion length of the photoanode, Ln, charge transport resistance, Rct and transport resistance, Rt. © 2015, Springer Science+Business Media New York.