Experimental and theoretical study of highly porous lignocellulose assisted metal oxide photoelectrodes for dye-sensitized solar cells

Abstract

Here, we have manufactured extremely porous photoelectrodes comprised of ZnO/TiO2 by adding lignocellulose (LC) fibers extracted from the self-growing plant (Lily) on fluorine-doped tin oxide (FTO) substrate using doctor blade technique for dye-sensitized solar cells (DSSCs) uses and first-principle calculations were performed for electronic band structures and density of state (DOS). Density functional theory (DFT) results revealed a high conductivity and narrow electronic bandgap after doping with LC. Experimental results showed the effect of the addition of LC in ZnO (ZnO + LC) and TiO2 (TiO2 + LC) on the structure, morphology, and power conversion efficiency (PCE) was studied in detail using powder X-ray diffraction, scanning electron microscope, UV–visible spectroscopy, and solar simulant. The addition of LC in ZnO/TiO2 increases the porosity and surface area for higher dye loading and light-harvesting while decreasing the backward scattering of electrons. These developments result in a 38% increase in PCE of (ZnO + LC) as related to the ZnO based DSSC and a 104% increase in the case of (TiO2 + LC) based DSSC. In this work, we express that the development of highly porous metal oxide nano-composites by mixing LC fibers which may solve the electrolyte leakage issue and enhance the porosity of the photoelectrodes and thus enhance the PCE of DSSCs.

Keywords

• ZnO/TiO2 nanocomposites
• Dye-sensitized solar cells
• Lignocellulose (LC) fibers
• First principal theory
• DFT