Maximization and minimization of interfacial thermal conductance by modulating the mass distribution of the interlayer

Tuning interfacial thermal conductance has been a key task for the thermal management of nanoelectronic devices. Here, we study how the interfacial thermal conductance is greatly influenced by modulating the mass distribution of the interlayer of one-dimensional atomic chain. By nonequilibrium Green's function and machine learning algorithm, the maximum/minimum value of thermal conductance and its corresponding mass distribution are calculated. Interestingly, the mass distribution corresponding to the maximum thermal conductance is not a simple function, such as the linear and exponential distribution predicted in previous works, it is similar to a sinusoidal curve around a linear distribution for larger thickness interlayer. Further, the mechanism of the abnormal results is explained by analyzing the phonon transmission spectra and density of states. Additionally, the mass distributions are applied to Si/Ge and Si/Siisotope three-dimensional systems. The work provides deep insight into optimizing and designing interfacial thermal conductance by modulating mass distribution of interlayer atoms.