Experimental conditions required for accurate measurements of electrical resistivity, thermal conductivity, and dimensionless figure of merit (<i>ZT</i>) using Harman and impedance spectroscopy methods

Beltrán-Pitarch, Braulio; Prado‐Gonjal, Jesús; Powell, Anthony V.; Garcı́a-Cañadas, Jorge

doi:10.1063/1.5077071

Cited by 21 publications

(18 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The film thickness is 0.5 μm. In the software analysis of these dependencies, first, from the frequency dependence of the imaginary component of the complex impedance, according to expression (1), the values of the parameters C1, R1 were found, and from the real component, the parameter R was estimated. The approximation was performed using the least-squares method.…”

Section: Development Of Software and Hardware And Discussion Of The Rmentioning

confidence: 99%

“…Many groups of scientists are carrying out a lot of research to increase it. In particular, semiconductor nanomaterials are promising for applications, due to the possibility of an independent increase in the Seebeck coefficient (S) and a decrease in thermal conductivity (κ) [1]. Such studies require the measurement of electrical conductivity, Seebeck coefficient, thermal conductivity, which, when using classical methods, is a rather laborious task, since the required samples are of various configurations.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Specialized Software and Hardware for Impedance Spectroscopy of Thermoelectric Energy Converters

Dunets¹,

Dzundza²,

Kostyuk³

2020

MEM

View full text Add to dashboard Cite

Section: Development Of Software and Hardware And Discussion Of The Rmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Specialized Software and Hardware for Impedance Spectroscopy of Thermoelectric Energy Converters

Dunets¹,

Dzundza²,

Kostyuk³

2020

MEM

View full text Add to dashboard Cite

“…Thermoelectric materials have been used for many years as a reliable solid-state technology for applications ranging from local cooling to waste heat utilization [1]. The achievements of recent years in the synthesis of semiconductor materials have led to an improvement in the conversion of thermal energy into electrical energy due to the nanostructuring of materials, and have expanded the application boundaries of thermoelectric energy [2,3].…”

Section: Literature Review and Problem Statementmentioning

confidence: 99%

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

Dunets

Dzundza

Turovska

et al. 2021

EEJET

View full text Add to dashboard Cite

Methods for studying thermoelectric parameters of semiconductors that are optimal for the implementation of software and hardware have been analyzed and selected. It is based on the Harman method and its modifications, adapted for pulse measurements, which are convenient to implement on a modern element base. An important advantage of these methods is the absence of the need for accurate measurements of heat fluxes, which greatly simplifies and reduces the time for conducting experimental research. The required operating ranges for the voltage 10 µV–1 V, for the current 10 µA–300 mA and the element base performance at the processing level of 40–200 million samples per second have been determined. Structural and electrical circuits, as well as software for a specialized computer system for studying thermoelectric parameters of both bulk and thin-film thermoelectric materials, and express analysis of the operational characteristics of finished modules have been developed. It has been shown that the proposed scheme copes well with the task. And the use of FPGA and 32-bit microcontrollers provide sufficient processing speed up to 200 MSPS and the necessary synchronization modes for the implementation of the Harman pulse method even when studying films of nanometer thickness. Experimental studies of both bulk thermoelectric modules based on Bi2Te3 and thin-film thermoelectric material based on PbTe have been carried out. The effectiveness of the developed tools and techniques has been shown, which made it possible to more than halve the time for sample preparation and experiment. Based on the presented models, all the main thermoelectric and operational parameters have been determined, in particular, electrical conductivity, Seebeck coefficient, thermal conductivity, thermoelectric figure of merit. As a result of the development of specialized computer tools, it was possible to reduce the labor intensity of the process of measuring the main electrical and operational parameters of semiconductor thermoelectric materials and energy conversion modules based on them, as well as to automate the process of defects identification of thermoelectric modules. The labor intensity of the research process has decreased not only due to the automation of the measurement process, but also due to an optimized technique that allows research on a sample of one configuration, since the manufacture and preparation of samples are the most laborious

show abstract

“…To characterize thermoelectric devices, Harman's method and power output measurements have been widely used to evaluate the ZT values and thermoelectric power, respectively, but additional extensive measurements are necessary to determine the three key parameters ( , S, and ). Recently, several studies have demonstrated that impedance spectroscopy can be used to determine the ZT values of thermoelectric bismuth telluride [29] and SKD [30,31] materials as well as bismuth telluride [32][33][34][35][36][37][38] and SKD [39,40] based devices. In a typical galvanostatic impedance spectroscopy measurement, a sinusoidal current perturbation drives the thermoelectric system slightly out of temperature equilibrium (appearance of a temperature gradient), inducing reorganization of the carriers owing to the Peltier effect, which allows the Seebeck voltage to be measured as a function of frequency.…”

Section: Introductionmentioning

confidence: 99%

Determination of the thermoelectric properties of a skutterudite-based device at practical operating temperatures by impedance spectroscopy

et al. 2019

Self Cite

View full text Add to dashboard Cite

Skutterudite-based thermoelectric materials are promising candidates for waste heat recovery applications at intermediate temperatures (300-500 °C) owing to their high dimensionless figure of merit and power factor. Recently, several researchers have reported the high performance of skutterudite-based thermoelectric devices obtained by optimizing the crystal structure and microstructure of skutterudite materials and developing metallization layers for device fabrication. Despite extensive research efforts toward maximizing the power density and thermoelectric conversion efficiency of skutterudite-based devices, the thermoelectric properties of such devices after fabrication remain largely unknown. Here, we systematically investigated the factors that affect the thermoelectric properties of skutterudite-based devices within the range of practical operating temperatures (23-450 °C). We successfully prepared a two-couple skutterudite-based device with titanium metallization layers on both sides of the thermoelectric legs and characterized it using scanning and transmission electron microscopy and specific contact resistance measurements. Impedance spectroscopy measurements of the two-couple skutterudite-based device revealed the figure of merit of the device and enabled the extraction of three key thermoelectric parameters (Seebeck coefficient, thermal conductivity, and electrical conductivity). The impedance spectra and extracted parameters depended strongly on the measurement temperature and were mainly attributable to the thermoelectric properties of skutterudite materials. These observations demonstrate the interplay between the properties of thermoelectric materials and devices and can aid in directing future research on thermoelectric device fabrication.

show abstract

Experimental conditions required for accurate measurements of electrical resistivity, thermal conductivity, and dimensionless figure of merit (ZT) using Harman and impedance spectroscopy methods

Cited by 21 publications

References 17 publications

Specialized Software and Hardware for Impedance Spectroscopy of Thermoelectric Energy Converters

Specialized Software and Hardware for Impedance Spectroscopy of Thermoelectric Energy Converters

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

Determination of the thermoelectric properties of a skutterudite-based device at practical operating temperatures by impedance spectroscopy

Contact Info

Product

Resources

About