Influence of Sodium Iodide doped polypyrrole on green synthesized aluminum doped ZnO for the enhanced charge separation at the interface

Abstract

Different Concentration of Aluminum (1, 3, 5%) was doped in ZnO by green synthesis method using environmental friendly cucum sativa fruit pulp extract as capping agent. Increase in crystallinity was observed for higher concentration of Aluminum in ZnO by X-ray diffraction (XRD). With the increase in Al percentage, band gap gets reduced from 3.14eV to 3.01eV, due to band tailing effect. On the other hand, Polypyrrole(PPy) and Sodium iodide(NaI) doped PPy powder synthesized by chemical polymerization method produced a band gap of 2.83eV and 2.57eV respectively. A simple and economical Successive ionic layer adsorption and reaction (SILAR) method was employed to fabricate 5% Al doped ZnO/NaI-PPy nanocomposite thin film. Characterization of the ZnO reveal enhanced crystallinity, spherical morphology and low band gap which has an influence in the Photoluminescence quenching of the nanocomposite thin film. To reveal the electronic property of ZnO with Al using density functional theory (DFT) was performed. Reduction in band gap well agreed with experimental finding. Our findings suggest that nanocomposite thin film can be fabricated with improved charge separation at the interface which can find application in Photo catalysis, hybrid solar cell and optoelectronic devices.