Investigation of CsPbBr₃ CVD dynamics at various temperatures

Since the emerging development of CsPbBr₃ perovskite, chemical vapor deposition (CVD) has become one of the most promising fabrication techniques by which to precisely deposit uniform perovskite thin films. However, there have been few reports on the growth dynamics and chemical reaction parameters (e.g., activation energy) for perovskite CVD. In this work, different deposition rates of CVD-grown CsPbBr₃ thin films were obtained at different substrate temperatures. Dynamics equations were developed to relate the inflow rates, desorption coefficients and concentrations of reactants on the substrates. Only a small amount of reactant became activated at low temperature and a small amount of PbBr₂ resided on the substrate at high temperature, and accordingly the maximal deposition rate was achieved at 250 °C. The Arrhenius activation energy of CVD-grown CsPbBr₃ was also calculated, and found to be 31.64 kJ mol^-1. We believe that our work provides a detailed picture of perovskite CVD growth.