A new type of low power thermoelectric micro-generator fabricated by nanowire array thermoelectric material

摘要

A new type of thermoelectric micro-generator, which is composed of n-type and p-type Bi_2Te_3 nanowire array thermoelectric materials, is designed to be energy source for miniaturized solid-state devices such as MEMS, micro-electrical system and even "system on a chip". The nanowire arrays are fabricated by electrochemical deposition ofBi_2Te_3 into the nano-pores of alumina template. The measurements showed that the Seebeck coefficient α of p-type and n-type Bi_2Te_3 nanowire arrays is about 260 and -188 μV/K separately with the nanowire diameter of about 50 nm at 307 K. The thermoelectric micro-generator is designed to possess a film like configuration and a laminar structure as C layer/B layer/A layer/B layer/C layer. The A layer is thermoelectric material layer consisting of a great amount of n-type and p-type nanowire micro-zones. Two B layers are electric conductive layers which realize the series electric connection of n-type and p-type micro-zones in A layer. The other two C layers are thermal conductive layers. By the use of IC technology, the micro-generator can obtain a high voltage output, and its thickness is less than 200 μm. The unique laminar structure makes thermo-electricity conversion more effective. An important aspect that distinguishes our device from the conventional one is that thermoelectric nanowire arrays are firstly used to fabricate thermoelectric micro-generator.