Microwave assisted green synthesis of ZnO nanorods for dye sensitized solar cell application

Abstract

The rod shaped ZnO nanoparticles have been synthesized for the first time in a biological process using <em>Colocasia esculenta</em> tuber extract. Moreover, the synthesized nanoparticles have been exposed to microwave irradiation followed by annealing at 400°C. Subsequently, the FESEM and TEM images shows rod shaped morphology of synthesized ZnO nanoparticles. In addition the XRD studies reveal that the prepared ZnO nanoparticles exhibit wurtzite phase with average particle size of 13.4 nm. The Tauc plot drawn with UV-Vis spectroscopy data confirms the band gap energy of green synthesized ZnO nanoparticles as 3.12 eV. The synthesized nanoparticle is used as a photoanode in dye sensitized solar cell for the first time. The photoanodes is sensitized using natural dyes prepared from the fruit extract of <em>Terminalia catappa</em>, flower extracts of <em>Callistemon </em><em>citrinus </em>and leaf extracts of <em>Euphorbia pulcherrima</em> and solar cell was fabricated. Its efficiency is found to be in the range of 1.29% to 1.60%.