Thermoelectric Response Characteristics of Bi2Te3 Based Semiconductor Materials

In actual operation, the operating environment temperature of thermoelectric devices are constantly changing and rarely remain stable, and the electrical output characteristics of thermoelectric devices are largely determined by thermoelectric materials. In response to this question, the thermoelectric properties of thermoelectric materials (p and n type Bi2Te3) are measured under different temperature difference environments. The Seebeck coefficient, resistivity, and thermal conductivity of the specimens at T = 300-600 K were measured by CTA-4 and CLA1000 (laser flash method), respectively; the thermal and electrical output responses of the thermoelectric materials under different temperature difference conditions were collected in real time by using a self-built thermoelectric performance test platform, thermal/electrical test system with infrared thermal imager, and voltage acquisition system, respectively. The experimental results show that when the temperature difference between the two ends of the specimen increases uniformly, the electrical output signal amplitude also increases uniformly; when the temperature difference is stable, the two ends of the specimen also produce a stable electrical output signal. After stabilization, the electrical output signal amplitude also decreases uniformly when the temperature decreases at a uniform rate. In the temperature range of 298 similar to 573 K, the larger the temperature difference between the two ends of the specimen was, the larger the amplitude of the electrical output signal was after stabilization; and vice versa. The greater the loading rate of the thermal load was, the greater the rate of increase of the electrical output signal amplitude at both ends of the specimen was, and the steady-state equilibrium time required was less.