Thermodynamic framework elucidating supersaturation throughout nanocrystal growth

Supersaturation is the fundamental thermodynamic parameter driving crystal nucleation and growth, yet no method can characterize it during the formation of colloidal nanocrystals (NCs). Here, we develop a framework to experimentally characterize time-resolved profiles of supersaturation throughout NC growth. As demonstrated with Au nanocubes, our methodology can predict the growth profiles of NCs and reveal supersaturation-associated shape evolutions. By altering supersaturation dynamics, we modulate these shape evolutions and NC features with atomic precision. This work paves the way for deeper understanding of the complex phenomena directing nanoscale crystal growth and provides insight for the rational design of NCs.