Thermodynamic Analyses of the Two-Step Method of CsPbBr3 Crystal Growth for Inorganic Perovskite Solar Cells

Abstract

We conducted integrated thermodynamic analyses for the two-step method of CsPbBr3 growth. Deriving from Gibbs free energy and heterogeneous nucleation theory, a thermodynamic reaction model equation was proposed and verified, from which we could find that the grainsizes of the CsPbBr3 can be precisely controlled by the CsBr concentration. The impact of temperature of the solvent was also studied. Finally, a best cell was fabricated showing a power conversion efficiency of 4.75%, with open circuit voltage of 1.13 V, short circuit current of 6.68 mA/cm2 and fill factor of 63%. Our results will help other researchers to determine the appropriate condition of the growth of CsPbBr3 by the two-step method.