How does the Peltier effect allow some semiconductors to provide refrigeration?

The Peltier effect describes the absorption or release of heat at the junction of two dissimilar conductors or semiconductors when an electric current flows through them.123

In the context of refrigeration, this phenomenon is made practical by using semiconductor thermocouples, such as those made from n-type and p-type bismuth telluride. These thermocouples are arranged electrically in series and thermally in parallel. When current passes through the circuit, a temperature difference develops between the junctions. By actively removing heat from the hotter junction, the second junction becomes significantly colder, allowing it to function as a refrigerator.23

These devices are highly valued in technology because they are compact, contain no moving mechanical parts, and can maintain precise, stable temperatures for cooling small objects.23