(a) Schematic of the direction of current and thermal gradient in the Peltier effect, where j_c represents the applied current density. The red and blue areas indicate temperature increase and decrease (N-type material), respectively. (b) A typical longitudinal TE device. The white rectangles at the top and bottom represent ceramic plates, while the red and blue rectangles represent P-type and N-type TE legs, connected in a Π-shape. (c) Schematic of the Ettingshausen effect, where H represents the applied magnetic field. The resulting thermal gradient is oriented perpendicular to both the applied magnetic field and the applied current directions. (d) Diagram of an infinite-stage Nernst-Ettingshausen device. (e) Schematic of the Thomson effect, where ∇T represents applied thermal gradient. For N-type materials, under the influence of the illustrated current and thermal gradient, the whole material exhibits heat absorption.