Precise Setup for Simultaneous Measurement of Thermoelectric and Electrophysical Properties of Thin Films in Wide Temperature Range

The most important characteristic of the efficiency of thermoelectric materials is dimensionless thermoelectric figure of merit ZT, which is determined for thin film materials to a large extent by the electrical conductivity σ and Seebeck coefficient α at the operating temperature T. Thus, the study of the temperature dependence of the efficiency of thermoelectric materials is associated with the need to simultaneously measure the temperature dependences of the conductivity and Seebeck coefficient in the wide temperature range. Such investigations require not only high accuracy, but also long time of the measurements, which is not always possible. This article presents the results of the development of the hardware-software complex for measuring the temperature dependences of the electrophysical and thermoelectric properties simultaneously for 8 samples of the electronic material films in the temperature range from −196 to 600°C. Temperature controller based on fuzzy logic is developed. Creation of accessory functions for input and output variables, and a rule base for linking input and output membership functions to configure the controller using fuzzy logic are described. The results of developing software for automation of the processes of measuring, processing and saving the results of experiments are presented.