Thermal decomposition of sol-gel derived Zn0.8Ga0.2O precursor-gel: A kinetic, thermodynamic, and DFT studies

Abstract Gallium-doped zinc oxide has been widely accepted as the potential alternative to expensive tin-doped indium oxide (ITO) for transparent conductive layer applications. An extensive study reports the processing of ZnO-based semiconductor materials by utilizing a sol-gel method, however, no study has been reported to investigate both the kinetic and thermodynamic aspects of the gel decomposition for these materials. Here, we studied the kinetic and thermodynamic parameters of the sol-gel derived Zn0.8Ga0.2O precursor gel decomposition utilizing the thermogravimetric (TG) and differential thermal analysis (DTA). A non-isothermal method was used to calculate the activation energy, pre-exponential factors, reaction mechanism function, and order of reaction. In addition, density functional theory (DFT) was used to calculate the optical band gap and density of states. The results suggested that the gel decomposition followed the Jander: 3D model. The study is important for understanding the components of synthesis ranging from the formation of an activated complex to gel decomposition, while this study can be extended to other semiconductor processing methods.