Realizing High Thermoelectric Performance of Bi-Sb-Te-Based Printed Films through Grain Interface Modification by an In Situ-Grown β-Cu2-δSe Phase

It has been a substantial challenge to develop a printed thermoelectric (TE) material with a figure-of-merit ZT > 1. In this work, high ZT p-type Bi0.5Sb1.5Te3-based printable TE materials have been advanced by interface modification of the TE grains with a nonstoichiometric beta-Cu2-delta Se-based inorganic binder (IB) through a facile printing-sintering process. Asa result, a very high TE power factor of, similar to 17.5 mu W cm(-1) K-2 for a p-type printed material is attained in the optimized compounds at room temperature (RT). In addition, a high ZT of similar to 1.2 at RT and of, similar to 1.55 at 360 K is realized using thermal conductivity (kappa) of a pellet made of the prepared printable material containing 10 wt % of IB. Using the same material for p-type TE legs and silver paste for n-type TE legs, a printed TE generator (print-TEG) of four thermocouples has been fabricated for demonstration. An open-circuit voltage (V-OC) of 14 mV and a maximum power output (P-max) of 1.7 mu W are achieved for Delta T = 40 K for the print-TEG.

Automated summary

Developing a printed thermoelectric material with high figure-of-merit has been a challenge, but this work successfully advanced high ZT p-type Bi0.5Sb1.5Te3 printable TE materials through interface modification. The optimized compounds showed high power output and a printed TE generator with promising results was fabricated for demonstration.