Addition of Organic Compounds in Gelatin-biopolymer Gel Electrolyte for Enhanced Dye-sensitized Solar Cells

Abstract

This chapter introduced a new series of organic compound additives like thiophene 2,5-dicarboxylic acid (TDA), sulfanilamide (SAA), 2,6-diamino pyridine (DAP), dibenzo-18-crown-6 (DBC) and 2,6-pyridine dicarboxylic acid (PDA) with gelatin/KI/I2 consist gel polymer electrolytes for dye-sensitized solar cells (DSSCs) application. Nowadays, it is focusing on biopolymers for preparing gel electrolytes for DSSCs application which is a conventional renewable energy source. Biopolymers are abundant in nature, and they are non-toxic, thermally stable, environmentally friendly, low-cost, and have good mechanical and physical properties. The introduced novel gelatin (GLN) biopolymer-based gel electrolytes play a role in improving ionic conductivity and stability, and it also play a better ability for ionic mobility. The low-cost and commercialized organic additive molecules with electron donors like S, O and N elements were strongly coordinated on the surface TiO2 and fermi level shift into negative potentials. The organic additive compound SAA achieved a very active additive and easily reduced the recombination reaction between the surface of TiO2 and I3− ions. This phenomenon readily improves the stability and overall η of the DSSC. During the DSSCs process, intrinsic charge carrier transfer between both electrodes as well as the continuous regeneration of the dye molecules. The surface study and conductivity of prepared gelatin-based gel electrolyte with N, S and O-based additives were characterized by fourier transform infrared spectroscopy (FTIR), UV-visible, X ray diifraction (XRD), Electrochemical Impedance Spectroscopy (EIS) and dye-sensitized solar cells (DSC), respectively. Furthermore, to examine the adsorption behaviour of organic additives on TiO2 (101) surface and negative fermi level shift on TiO2 surface were analysed by density functional theory (DFT) theoretical study.