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

► The ZnO nanosheets (ZNONSs) are synthesized via simple hydrothermal method. ► The dye-sensitized solar cell (DSSC) is fabricated using ZnONSs and a low-cost organic dye. ► Its performance in DSSC with TiO 2 nanotubes modified polymer electrolyte is studied. ► The ZnONSs based DSSCs show higher conversion efficiency than ZnO nanoparticles based DSSCs. ► This is attributed to the fast electron diffusion within the nanosheets. 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 TiO 2 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.