Depletion forces, commonly modeled with rigid body assumptions, inadequately describe nanoparticle behavior. This study introduces the roles of Soret and Dufour effects in nanoparticle systems, focusing on mass and energy gradient interchange. The Dufour effect drives energy flow through mass gradients, which implies the possibility of driving the energy flow near the nanoparticles to induce phase transitions via manipulating the monomer concentrations. Our experimental platform confirmed these theories, synthesizing HCP quantum dots from Au, Ag, Pd, and mixed halide perovskites under varied precursor concentrations. By analyzing energy flow and nucleation dynamics through the Dufour effect, we mapped phase transition thresholds, linking them to material entropy. This study provides insight into nanoparticle assembly and phase behavior, highlighting the significance of entropy in nucleation dynamics.