Thermoelectric generator and solid-state battery for stand-alone microsystems

Abstract

This paper presents a thermoelectric (TE) generator and a solid-state battery for powering microsystems. Prototypes of TE generators were fabricated and characterized. The TE generator is a planar microstructure based on thin films of n-type bismuth telluride (Bi2Te3) and p-type antimony telluride (Sb2Te3), which were deposited using co-evaporation. The measurements on selected samples of Bi2Te3 and Sb2Te3 thin films indicated a Seebeck coefficient in the range of 90–250 μV K−1 and an in-plane electrical resistivity in the range of 7–17 μÄ m. The measurements also showed TE figures-of-merit, ZT, at room temperatures (T = 300 K) of 0.97 and 0.56, for thin films of Bi2Te3 and Sb2Te3, respectively (equivalent to a power factor, PF, of 4.87 mW K−2 m−1 and 2.81 mW K−2 m−1). The solid-state battery is based on thin films of: an anode of tin dioxide (SnO2), an electrolyte of lithium phosphorus oxynitride (LixPOyNz, known as LiPON) and a cathode of lithium cobaltate (LiCoO2, known as LiCO), which were deposited using the reactive RF (radio-frequency) sputtering. The deposition and characterization results of these thin-films layers are also reported in this paper.