A kind of measuring device and method of thin film thermoelectric performance parameters

Abstract

The invention provides a device and a method for measuring thermoelectric parameters of a film. The measuring device, which has a symmetric structure, comprises a radiating fin, a thermoelectric module, a heat insulation material, metal round rods, a thermocouple wire, a voltmeter, a power supply, a data acquisition instrument and a computer. The measuring method provided by the invention comprises the following steps of: clamping a film to be measured between two upper and lower metal round rods which are completely same while the area of the film sample is the same as the cross-sectional area of the metal round rods, controlling the ambient temperature of the measuring device and the heat flow of the film sample by the use of the thermoelectric module, detecting and recording each performance parameter of the film thermoelectric material at real time by the use of the data acquisition instrument. The invention has the following advantages: the performance of the film thermoelectric material at different temperatures can be measured, that is to say, the same device can be utilized to simultaneously measure the thermal conductivity coefficient, Seebeck coefficient and conductance coefficient of the film thermoelectric material so as to calculate ZT values of the film thermoelectric material at different temperatures. According to the invention, the measuring device has a simple principle, is convenient to operate, is small in size, has many test functions and has high measuring precision.

Description

technical field [0001] The invention belongs to the technical field of material performance testing, and in particular relates to a device and method for measuring thermoelectric performance parameters of thin films, which can measure thermoelectric performance parameters in a direction perpendicular to the plane of the thin film. Background technique [0002] At present, the study of thermoelectric materials has become a hot spot in the field of materials. The performance of thermoelectric materials is usually determined by a dimensionless figure of merit ZT value to measure, its specific expression is ,in S is the Seebeck coefficient, σ is the conductance coefficient, kappa is the thermal conductivity, T is the temperature. Therefore, for thermoelectric materials, thermal conductivity, Seebeck coefficient, and electrical conductivity are the three most important performance parameters. Accurate determination of these parameters is of great value and signi...

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Problems solved by technology

[0003] However, the current measurement devices involving thermal conductivity, Seebeck coefficient and electrical conductivity mainly have the following problems: 1. The measurement of material thermal conductivity, Seebeck coefficient and electrical conductivity is basically carried out separately through different measuring devices Yes, the thermal conductivity is obtained by the steady-state method or the transient method, the Seebeck coefficient is usually measured by the temperature difference method at both ends, and the electrical conductivity is mostly measured by the four-wire or two-wire system

This evaluation of overall thermoelectric performance with different measurement setups (i.e. ZT value) cannot avoid introducing large errors, and there is no related device that can simultaneously measure the thermal conductivity, Seebeck coefficient and electrical conductivity of thermoelectric materials

2. Some existing thermoelectric performance evaluation systems can only measure the performance of bulk thermoelectric materials, but are not able to measure the properties of thin films or thin sheets

3. In the existing thermal conductivity and Seebeck coefficient measurement devices, the usual way to control the temperature difference is to install a temperature-controlled fluid device at both ends of the sample, and adjust the power of the heater and refrigerator. Fluid temperature, so as to generate a temperature difference at both ends of the sample, but the temperature difference generated in this way is complicated and the accuracy is not high

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