Inkjet Printing of Single‐Crystalline Bi2Te3 Thermoelectric Nanowire Networks

Abstract

Large‐scale and low‐cost fabrication techniques are needed to commercialize highly efficient, nanomaterial‐based thermoelectric generators (TEGs) for use in small‐scale, flexible applications (e.g., wearable energy harvesters). This study presents the first demonstration of inkjet‐printed networks of phase‐pure, single‐crystalline Bi2Te3 thermoelectric nanowires (BTNWs) that are amenable to large‐scale production. The BTNWs are synthesized via chemical batch processing and formulated into a jettable ink that is printed onto glass substrates and subsequently annealed in nitrogen and forming gas environments. The inkjet‐printed BTNWs annealed in forming gas provide the most favorable results with comparable thermoelectric performances to bulk Bi2Te3 materials (Seebeck coefficient up to 140 µV K−1) while approximately utilizing only 1% to 3% of the telluride materials found in their bulk counterparts. Thus, these printed BTNWs help pave the way for the development of low‐cost and scalable TEGs.