Apparatus for Seebeck coefficient measurement of wire, thin film, and bulk materials in the wide temperature range (80–650 K)

Abstract

A Seebeck coefficient measurement apparatus has been designed and developed, which is very effective for accurate characterization of different type of samples in a wide temperature range (80 -650K) simultaneously covering low as well as high temperature regime. Reducing complexity of technical design of sample holder and data collections has always been challenging to implement in a single instrument when samples are in different geometrical shape and electronic structure. Our unique design of sample holder with pressure probes covers measurements of different samples shapes (wires, thin films and pellets) as well as different resistivity ranges (metals, semiconductors and insulators). It is suitable for characterization of different samples sizes (3-12 mm). A double heater configuration powered by a dual channel source meter is employed for maintaining a desired constant temperature difference across the sample for the whole temperature range. Two K-type thermocouples are used for simultaneously reading of temperatures and Seebeck voltages by utilizing different channels of a multichannel digital multimeter. Calibration of the system has been carried out using constantan, chromel and alumel materials and recorded data is found to be very accurate and consistent with earlier reports. The Seebeck coefficients of standard samples of constantan (wire) and GaN (thin film) have been reported, which shows the measurement capability of designed setup with versatile samples.

Wide range temperature-dependent (80–630 K) study of Hall effect and the Seebeck coefficient of β -Ga2O3 single crystals

“…Two distinct regions with different slopes above and below of 300 K can be seen. Similar temperature dependence behavior has also been reported in other wide bandgap semiconductors like GaN [21,24] having similar carrier concentrations (n=2×10 18 cm −3 ).…”

“…The circular contact pads of 0.5 mm diameter were fabricated at the two opposite edges of rectangular samples (2×5 mm 2 ) for thermoelectric measurements, and at four corners of square samples (5×5 mm 2 ) in van der Pauw geometry for electrical characterizations (separate pieces from the same wafer). The Seebeck coefficient measurement was performed in the temperature range of 80-630 K using an in-house developed system [21]. A pre-measurement calibration of the system using a constantan standard was done.…”

Specialized Software and Hardware for Impedance Spectroscopy of Thermoelectric Energy Converters

“…The average error in measuring the figure of merit is 20% including an error in measuring individual thermoelectric parameters of about 5%. In [7], based on LabVIEW expansion card and a precision electrometer, a system for direct studies of thermoelectric characteristics by the differential method is presented. The to the specified parameters.…”

Features for the design of a specialized information-measuring system for the study of thermoelectric properties of semiconductors

“…The selected methods and models (5), ( 6) made it possible to implement the entire complex of studies on a sample of one configuration (Fig. 1), which significantly reduced the labor intensity and time for preparing the experiment in comparison with classical methods [1,9,10]. In addition, the described research methods and tools are non-destructive and do not require, for example, drilling a sample to determine thermal conductivity, as in the radial flow method.…”

“…This leads to large errors in determining the properties, complicates the comparison of the results obtained by different groups and the comparison of the efficiency of new thermoelectric materials. The work [10] presents a system for direct studies of thermoelectric characteristics by a differential method based on LabVIEW expansion cards (National Instruments, USA), precision electrometer, and using chromel-alumel thermocouples for measuring the temperature difference created by a gradient heater.…”