Photovoltaic performance of solid-state solar cells based on ZnO nanosheets sensitized with low-cost metal-free organic dye

Abstract

In this study, the fabrication of photoanode of dye-sensitized solar cell (DSSC) using two-dimensional ZnO nanosheets (ZnONSs) and low-cost metal-free photosensitizer, evans blue, and evaluation of its photovoltaic performance in the solid-state DSSC with TiO2 nanotubes (TNTs) modified poly(ethylene oxide) (PEO) polymer electrolyte is described. The ZnONSs are synthesized via hydrothermal method and are characterized by high resolution scanning electron microscopy (HR-SEM), diffuse reflectance spectroscopy (DRS), photoluminescence spectroscopy (PLS) and X-ray diffraction (XRD) analysis. The photovoltaic performance of the cells is evaluated under standard air mass 1.5 global simulated illumination (100 mW cm^-2). The current-voltage (I-V) and photocurrent-time (I-T) curves proved effective collection of electrons in the solid-state DSSCs with the ZnONSs photoanode. The solar to electrical energy conversion efficiency of the ZnONSs based DSSC with TNTs modified PEO electrolyte is 0.12%, which is about 1.5 times higher than that of the ZnO nanoparticles based DSSC, due to fast electron diffusion within the nanosheets.