Fabrication of Oxide Thermoelectric Module Consisting of Multi-Layered Thick Films

We report the fabrication and thermoelectric properties of a multi-layered unicouple of [Ca
₂
CoO
_3-delta
]
_0.62
CoO
₂
(Ca349; p-type) and Ca
_0.9
La
_0.1
MnO
_3-delta
(Mn113; n-type). The multi-layered thick films consisting of Ca349, Mn113 and Al
₂
O
₃
were prepared using an electrophoretic deposition (EPD) method. In particular, the Ca349 layer was deposited under a magnetic field of 3 T and strongly c-axis-grain-oriented microstructure was obtained. The unicouple of hot-forged Ca349 and Mn113 layers generated 85 mV of voltage in DeltaT ~450 K and, however, showed remarkably high internal resistance due to porous microstructure of the Mn113 layer. The development of a densification process for the n-type layer is an important for improving higher power density