Creation of multisectional thermoelements for increasing of the efficiency of thermoelectric devices

The ways of increasing the efficiency of thermoelectric devices were considered. It was determined that in addition to the search of new semiconductor materials with high thermoelectric figure of merit it is advisable to use multisectional thermoelements (TE) in the construction of thermoelectric devices. Compositions of the effective thermoelectric materials (TEM) were proposed for the operating temperature range from 200 to 1200 K. Their thermal and electrophysical parameters were investigated, and temperature dependences of thermoelectric figure of merit were calculated. On the basis of the obtained results operating temperature ranges for TEM were determined, which were used in the multisectional TE. The structure, composition and fabrication methods of the multilayer contact system for all proposed TEM were developed. The contact system allows reliable commutation of different TEM in TE, providing minimal heat and electrical losses. The contact systems have low resistivity and high adhesion strength. The technique and mathematical model for the calculation and optimization of the multisectional TE constructions were developed, which are based on the use of the thermal and electrophysical parameters and operating temperatures. Construction of the multisectional TE with the operating temperature range from 300 to 1200 K was developed. The efficiency dependences on the temperature difference between the hot and cold junctions for the multisectional and common TE in the temperature range up to 1200 K were calculated. Obtained results shows sufficient advantage of the multisectional TE.