Thermoelectric Pellets

Thermoelectric pellets are small, precisely manufactured semiconductor elements typically composed of bismuth telluride (Bi2Te3) or similar compounds, engineered to exhibit strong thermoelectric properties. These pellets function as the core active components in thermoelectric modules (TEMs), where they are arranged electrically in series and thermally in parallel between ceramic substrates. When a temperature gradient is applied across the pellet, charge carriers (electrons or holes) diffuse from the hot side to the cold side, generating a measurable voltage (Seebeck effect for power generation). Conversely, applying electrical current forces heat absorption at one junction and release at the other (Peltier effect for active heating/cooling). Their performance is quantified by the dimensionless figure of merit (ZT), which depends on the Seebeck coefficient, electrical conductivity, and thermal conductivity of the material.

Thermoelectric pellets operate based on the Seebeck effect (for power generation) and Peltier effect (for heating/cooling). In the Seebeck effect, a temperature difference across the pellet causes diffusion of charge carriers, creating an electric potential. In the Peltier effect, an applied electric current causes heat absorption at one junction and heat dissipation at the other, enabling precise thermal management. The efficiency depends on the material's thermoelectric properties, optimized to maximize the Seebeck coefficient and electrical conductivity while minimizing thermal conductivity.