Green synthesis of Au and the impact of Au on the efficiency of TiO2 based dye sensitized solar cell

Abstract

Gold nanoparticles (AuNPs) were prepared through green synthesis route with the aqueous extract from the leaves of Phyllanthus embilica (commonly known as emblic or amla or thoppunelli) without using any surfactant and stabilizer. The synthesized AuNPs colloid was mixed in titanium dioxide slurry to yield Au:TiO2 nanocomposite. The as-synthesized AuNPs and Au:TiO2 nanocomposite were investigated for structural, optical and morphological properties. The dye sensitized solar cells (DSSC) using pure TiO2 and Au:TiO2 nanocomposite photoelectrodes were fabricated and their execution was studied. The efficiency of Au:TiO2 nanocomposite DSSC is improved by about 65% when correlated to the efficiency of the pure TiO2 DSSC. The electrochemical impedance spectroscopic assessment was performed to calculate the transport resistance and lifetime of electron. They decrease in the transport resistance which is accountable for the enhanced electron injection into the photoelectrode was studied using Nyquist plots. The Bode phase plot confirms the lifetime of electron in Au:TiO2 nanocomposite film is greater than that in the pure TiO2 film.