Deposition and Fabrication of Sputtered Bismuth Telluride and Antimony Telluride for Microscale Thermoelectric Energy Harvesters

Thermoelectric (TE) n-type bismuth telluride (Bi2Te3) films and p-type antimony telluride (Sb2Te3) films are grown on SiO2/Si substrates via radio frequency magnetron sputtering. The crystal structures and TE properties are characterized for 1 mu m and 10 mu m films deposited using different deposition conditions and using various heat treatment conditions. Single-target sputtered deposition of n-type Bi2Te3 films resulted in a Te-deficient off stoichiometric films due to the evaporation of tellurium. Two-target co-sputtered deposition using Bi2Te3 and Te targets at room temperature and subsequent anneal at 250 degrees C yielded a 10 mu m n-type film with -102 mu V/K for the Seebeck coefficient and 0.7 mW/K-2.m for the power factor. Similarly, prepared p-type Sb2Te3 film but using a single sputtering target yielded +110 mu V/K and 1.3 mW/K-2.m for their Seebeck coefficient and power factor respectively. The fabrication of the micro-scale thermoelectric energy generator (mu TEG) using separate n-type and p-type wafers is demonstrated.

Automated summary

TE n-type bismuth telluride (Bi2Te3) and p-type antimony telluride (Sb2Te3) films were successfully grown on SiO2/Si substrates via radio frequency magnetron sputtering in this study. The characterization of crystal structures and TE properties showed promising Seebeck coefficients and power factors under different deposition conditions and heat treatment conditions. The fabrication of a micro-scale thermoelectric energy generator (μTEG) using separate n-type and p-type wafers was demonstrated.