Growth kinetics of CsPbBr3 perovskite nanocrystals: Effects of stirring speed

Abstract

Understanding the growth behavior of semiconductor nanocrystals plays an important role in controlling the sizes of the formed nanocrystals. In this work, we investigate the growth behavior of inorganic CsPbBr₃ nanocrystals. The synthesis of CsPbBr₃ nanocrystals is performed using an antisolvent method under stirring. The temporal evolution of the photoluminescence peak wavelength during stirring is used to determine the nominal activation energies and the growth index for the growth of CsPbBr₃ nanocrystals under different growth conditions. Increasing the stirring speed from 0 rpm to 1000 rpm leads to an increase in the nominal activation energy from 8.34 kJ/mol to 14.13 kJ/mol and the growth index from 1.04 to 1.85. X-ray diffraction is used to analyze the size evolution of CsPbBr₃ nanocrystals formed at 308 K under different stirring speeds and under a stirring speed of 800 rpm at different temperatures. The X-ray diffraction analysis of the temperature effect on the average sizes of CsPbBr₃ nanocrystals yields a nominal activation energy of 13.44 kJ/mol for the CsPbBr₃ nanocrystals grown under the stirring speed of 800 rpm, which is comparable to 12.59 kJ/mol determined from the photoluminescence peak wavelength of the corresponding solutions. The method presented in this work offers a simple method to analyze the growth kinetics of semiconductor nanocrystals in liquid solutions.