Effect of Seed Layer on the Morphology of ‎Zinc Oxide Nanorods as an Electron ‎Transport Layer in Polymer Solar Cells ‎

Abstract

<em> Zinc oxide has been considered as a promising semiconductor material for fabrication of transparent conductive oxides (TCOs), electronic devices, optoelectronics, and solar cells.</em> <em>Among the various morphologies of zinc oxide, nanorods are more widely used because of the ease of synthesis and providing a direct path for the transport of charge carriers. The electrochemical deposition method (ECD), due to its simplicity, low cost, and production of nanostructures with fewer defects is a more suitable method for producing zinc oxide nanorods.</em> <em>Heretofore, the effect of different parameters such as the temperature of growth solution, the concentration of precursors and pH </em><em>on the morphology of the final product were studied</em><em>.</em> <em>In this paper, the effect of the seed layer number on morphology, absorption, and electrical conductivity of zinc oxide nanorods was investigated using SEM images, UV-Vis spectroscopy, and four-point probe. The results showed that increasing the number of seed layers from 0 to 5 lead to the production of vertical, uniform, regular, and high-density nanorods.</em> <em>Also, the use of high-density zinc oxide nanorods, in the structure of polymer solar cells increased the performance of polymer solar cells by 68%.</em> <em>The polymer solar cell with zinc oxide nanorods as the electron transport layer showed short-circuit current, open-circuit voltage, and the power conversion efficiency of equal to 9.04</em> mA/cm²<em>, 0.53V, and 2.51%, respectively.</em>