Fully 3D Printed Tin Selenide (SnSe) Thermoelectric Generators with Alternating n -Type and p- Type Legs.

Tin selenide (SnSe) has attracted much attention in the field of thermoelectrics since the discovery of the record figure of merit ( zT ) of 2.6 ± 0.3. While there have been many publications on p- type SnSe, to manufacture efficient SnSe thermoelectric generators, an n- type is also required. Publications on n- type SnSe, however, are limited. This paper reports a pseudo-3D-printing technique to fabricate bulk n- type SnSe elements, by utilizing Bi as a dopant. Various Bi doping levels are investigated and characterized over a wide range of temperatures and through multiple thermal cycles. Stable n- type SnSe elements are then combined with printed p- type SnSe elements to fabricate a fully printed alternating n- and p- type thermoelectric generator, which is shown to produce 145 μW at 774 K.