A comparison of power factor in n and p-type SiGe nanowires for thermoelectric applications

This work presents the thermoelectric properties of n- and p-type doped SiGe nanowires and shows the potential to generate electricity from heat difference over nanowires. The Si_0.74Ge_0.26 layers were grown by reduced pressure chemical vapor deposition technique on silicon on insulator and were condensed to the final Si_0.53Ge_0.47 layer with thickness of 52 nm. The nanowires were formed by using sidewall transfer lithography (STL) technique at a targeted width of 60 nm. A high volume of NWs is produced per wafer in a time efficient manner and with high quality using this technique. The results demonstrate high Seebeck coefficient in both n- and p-types SiGe nanowires. N-type SiGe nanowires show significantly higher Seebeck coefficient and power factor compared to p-type SiGe nanowires near room temperature. These results are promising and the devised STL technique may pave the way to apply a Si compatible process for manufacturing SiGe-based TE modules for industrial applications.