Performance evaluation of silicon nanowire arrays based thermoelectric generators

Abstract

Thermoelectric generators (TEGs) can improve the net power consumption of electronic packages by generating power from the chip waste heat. In this study, a 3D computational model of electronic package with silicon nanowire (Si-NW) based embedded TEGs has been developed and the effect of crucial geometric parameters, contact resistances and thermal properties such as pitch length and length of Si-NWs, the electrical contact resistivity at Si-NW interface, thermal contact resistivity at TEG-package interface, and filling material thermal-conductivity on power generation has been evaluated. The analysis has shown how modifying some crucial parameters from their current values in different experimental studies affect power generation, e.g., decreasing the pitch length from 400 nm to 200 nm double the power generation, increasing the Si-NW length from 1 μm to 8 μm increases power generation by a factor of three and decreasing contact resistivity by one order of magnitude from 1.0×10-11 Ω-m2 enhances the power generation by a factor of two. This study has estimated the energy conversion efficiency of 0.02 % for 8 μm long Si-NWs using the best thermo-electric properties available from different experimental studies. Finally, the analysis provides insights into the crucial parameters of Si-NW TEGs which should be focus of the future studies.