Coupling of Organic and Inorganic Vibrational States and Their Thermal Transport in Nanocrystal Arrays

Through atomistic computational analysis of thermal transport in nanocrystal arrays (NCAs), we find that vibrational states couple elastically across the organic-inorganic interfaces with a resulting flux that depends on the ligand grafting density and the overlap between the core and ligand vibrational spectra. The modeling was performed using molecular dynamics simulations and lattice dynamics calculations on a gold-dodecanethiol NCA built using a robust self-assembly methodology. Our approach is validated by comparing the predicted NCA thermal conductivities against experimental measurements [Ong et al. Nat. Mater. 2013, 12, 410], with agreement found in both magnitude and trends. The self-assembly methodology enables prediction of general NCA behavior and detailed probing of experimentally inaccessible nanoscale phenomena.