termoelektrilistes

Thermoelectricity refers to the direct conversion of temperature differences to electric voltage and vice versa. This phenomenon is explained by three interconnected effects: the Seebeck effect, the Peltier effect, and the Thomson effect.

The Seebeck effect is the most commonly utilized thermoelectric effect. It describes how a voltage is produced when the junctions of two different conductors or semiconductors are at different temperatures. This voltage is proportional to the temperature difference. Thermoelectric generators (TEGs) exploit this effect to produce electricity from heat sources.

The Peltier effect is the inverse of the Seebeck effect. It states that when an electric current flows through a junction of two different conductors, heat is absorbed or released at that junction. If the current flows in one direction, heat is absorbed, causing cooling. If the current flows in the opposite direction, heat is released, causing heating. This principle is used in thermoelectric coolers (TECs), often found in small refrigerators and cooling devices.

The Thomson effect describes the heating or cooling that occurs in a single homogeneous conductor when a temperature gradient exists along it and an electric current flows through it. This effect is generally less significant than the Seebeck and Peltier effects for practical applications.

Thermoelectric materials are crucial for these effects. They are typically semiconductors that exhibit good thermoelectric properties, meaning they have a high Seebeck coefficient, low thermal conductivity, and reasonable electrical conductivity. Research continues to focus on developing more efficient and cost-effective thermoelectric materials for a wider range of applications, including waste heat recovery and solid-state cooling.