An in-situ characterization device for extremely low thermal conductivity at the nanoscale

Abstract

This application discloses an in-situ characterization device for extremely low thermal conductivity at the nanometer scale, which is used to detect the micro-region thermal conductivity of a sample of a thermoelectric material to be tested, including: a nanoscale thermal signal in-situ excitation module for in-situ excitation Double-frequency and triple-frequency thermal signals related to the micro-region thermal conductance before and after the contact of the tested material; a nanoscale thermal signal in-situ detection module, used to realize the double-frequency and triple-frequency thermal signals In-situ real-time detection and processing, and display the in-situ characterization results of micro-area thermal conductivity; the heating frequency of the thermoelectric probe is in the range of 90Hz to 760Hz, ΔV 3ω It has a linear relationship with lnω, and according to the slope of its linear part, the thermal conductivity λ of the micro-area can be quantitatively characterized s . This application combines the nano-detection function of the atomic force microscope, the Joule heating effect of the probe, the three-fold frequency excitation of the thermal detection and the line heat source model, and establishes an in-situ characterization device based on the atomic force microscope with extremely low thermal conductivity at the nanometer scale.

Description

technical field [0001] The application belongs to the field of signal detection instruments, and in particular relates to an in-situ characterization device with nanoscale extremely low thermal conductivity. Background technique [0002] Thermoelectric materials based on the mutual conversion effect of heat energy and electric energy have become an important clean energy material at present, and have important applications in the fields of thermoelectric power generation and thermoelectric refrigeration, such as efficient multi-level utilization of industrial waste heat, environmental protection energy recovery, special power supplies, High-power electronic technology and miniature refrigeration, etc. Thermoelectric materials and devices with high performance and high thermoelectric conversion efficiency require materials with unique properties such as high electrical conductivity and low thermal conductivity. Thermal conductivity is a key parameter affecting the energy con...

AI Technical Summary

Problems solved by technology

However, microscopic factors such as nanosecond phases and grain boundaries have not been deeply studied on thermoelectric properties. It is urgent to develop new methods to realize the in-situ characterization of nanoscale thermoelectric parameters, so as to establish the relationship between various microscopic factors and electrothermal transport. , to promote the design and optimization of high-performance thermoelectric materials and thermoelectric devices

[0004] At present, the measurement techniques of macroscopic thermal conductivity, such as steady-state measurement method and unsteady-state method, are difficult to meet the urgent needs of microscopic thermal conductivity measurement.

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