Driving perpendicular heat flow: p x n transverse thermoelectrics for microscale and cryogenic peltier cooling
Chuanle Zhou, S. Birner, Yang Tang, K. Heinselman, and M. Grayson
Accepted
Whereas thermoelectric performance is normally limited by the figure of merit $ZT$, transverse thermoelectrics can achieve arbitrarily large temperature differences in a single leg even with inferior $ZT$ by being geometrically tapered. We introduce a band-engineered transverse thermoelectric with $p$-type Seebeck in one direction and $n$-type orthogonal, resulting in off-diagonal terms that drive heat flow transverse to electrical current. Such materials are advantageous for microscale devices and cryogenic temperatures -- exactly the regimes where standard longitudinal thermoelectrics fail. InAs/GaSb type II superlattices are shown to have the appropriate band structure for use as a transverse thermoelectric.