Preparation and thermoelectric characterization of phosphorus-doped Si nanocrystals/silicon oxide multilayers

摘要

Phosphorus-doped silicon nanocrystals (Si-NCs)/silicon oxide (SiOy) multilayers were prepared by plasma enhanced chemical vapor deposition and post-annealing. After annealing, Si-rich amorphous silicon oxide (a-SiOx) and a-SiOy layer were converted into a Si-NCs layer and lowly thermal conductive layer, respectively. The diameter of Si-NCs were changed by varying the thickness of a-SiOx layer from 3 to 10 nm. Electrical and thermal conductivity of Si-NCs/SiOy multilayers were decreased with decreasing the diameter (d) of Si-NCs. Thermal conductivity at d = 3 nm was estimated at 1.48 W m(-1) K-1, which is much lower than that of bulk silicon. These results show that phosphorus doped Si-NCs/SiOy multilayers are promising for thermoelectric materials. (C) 2020 The Japan Society of Applied Physics