The Demonstration of 3-D Bi_2.0Te_2.7Se_0.3/Bi_0.4Te_3.0Sb_1.6 Thermoelectric Devices by Ionized Sputter System

In this brief, we propose and demonstrate the Bi_2.0Te_2.7Se_0.3/Bi_0.4Te_3.0Sb_1.6 thermoelectric (TE) device with the 3-D structure through the manufacturing process by the ionized sputter system. With the same top-point-of-view area, the proposed 3-D TE device in this brief has approximately twice the number of n-/p-junctions than that in our previously demonstrated 2-D TE device. In order to extract the Seebeck coefficient (S) and the electrical conductivity (σ) to evaluate the total efficiency in our TE device, we also build up the accurate measurement systems. It can be found that the S value is improved ∼25% successfully in our proposed 3-D TE device with the same TE material thickness (t) of 100 nm. On the other hand, the power factor is also found to be enhanced to ∼50% accordingly. In summary, the figure of merit (ZT) - i.e., the ability of a TE device to efficiently produce electricity - is increased to ∼50% and achieves a value of 0.9, which is the highly competitive number at the low operating temperature (T) of 130 °C in our proposed 3-D TE devices in this brief.