Extraction, preparation and application of dyes from persicaria lapathifolia (flowers and roots) as sensitizers for dye sensitized solar cell

Abstract

Dye sensitized solar cell (DSSC) is a photovoltaic device that converts light energy into electrical energy that is composed of dyed working electrode, electrolyte and counter electrode. The dye molecules adsorbed on TiO 2 surface are responsible for light absorption. Accordingly, as this study was aimed to extract, prepare and use dyes from flowers and roots of Persicaria lapathifolia as sensitizer for dye sensitized solar cell (DSSC); two DSSCs one for flower extract and one for root extract were prepared by Doctor‘s Blade method. These dyes showed good absorption in visible range and optically responsible compounds were phytochemically screened. The electrochemical behavior and optical absorption property of flower and roots dyes were estimated by cyclic voltammetry and spectrophotometry (UVVis) respectively. As a result HOMO of flower extract dye was 0.322 eV and LUMO was -1.538 eV. While HOMO of root extract dye was 0.306 eV and LUMO of root was -1.594 eV. I-V and P-V curves were plotted by using Extech Multimeter, fluorescent lamp and electrical circuit made from resistors connected on wood board. Finally based on characterization of DSSC made from flower with efficiency (𝜂=2.49%) whereas the DSSC made from root with efficiency (𝜂= 1.93%) were obtained. Therefore, according to this work flower dye sensitized DSSC is more efficient than root dye sensitized DSSC. However, this work needs improvement to be scaled up based on recommendation set and seeks further study, too.