Computational fluid dynamics modeling and experimental investigation of a chemical vapor deposition synthesis of ZnO nanostructures

Abstract

Zinc oxide (ZnO) thin films and nanostructures have received extensive attention as important materials for various applications in field-effect transistors, gas sensors, dye-sensitized solar cell, and ultraviolet photodetectors. Thermal transport methods are some of the most common synthesis methods, due perhaps to the relative simplicity of the experimental setup which involves a temperature-controlled tube furnace and pure Zn as starting material. Thin films and nanostructures with various morphologies and sizes can be obtained using this method and varying experimental parameters such as synthesis temperature, air or oxygen flow rate, morphology of Zn sources, position of substrate, etc. So far, most researchers have used quasi-empirical methods to determine the optimum growth conditions for specific ZnO morphologies. The purpose of this research is to use computational fluid dynamics (CFD) to understand the influence of thermal evaporation parameters (furnace temperature, gas flow, substrate position) on the morphology and size of ZnO nanostructures. ZnO synthesis was performed under controlled conditions and the products were analyzed via scanning electron microscopy (SEM) analysis. The process was then simulated numerically using two- and three-dimensional models in ANSYS Fluent 16.1.0 software.