Quantitatively predicting modal thermal conductivity of nanocrystalline Si by full-band Monte Carlo simulations

Thermal transport of nanocrystalline Si is great importance for the application thermoelectrics. A better understanding modal thermal conductivity will be expected to benefit efficiency In this work, variance reduced Monte Carlo simulation with full band phonon dispersion applied study Si. Importantly, transmissions across grain boundaries which are modeled by amorphous interface calculated mode-resolved atomistic Greens function method. The predicted ratios that bulk agree well experimental measurements in a wide range size. decreased from 54 percent 3 and contribution phonons mean free path larger than size increases 30 96 percnet as decreases 550 nm 10 nm. This work demonstrates using transmission method can capture picture complex nanostructures, therefore provide guidance designing high performance based