Peltier Element
The Peltier element is the change in temperature produced at a junction between two metals or semiconductors when an electric charge so passed through it. The temperature changes is proportional to the current.
The reverse effect where a temperature difference results in an emf (electromotive force) is known as the Seebeck effect.

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explanation of the peltier effect
www.tf.uni-kiel.de/matwis/amat/elmat_en/kap_2/advanced/t2_3_2.html
explanation of the Seebeck effect