A p-type cu with excess copper 3.9 ga 4.2 te 8 Base medium temperature thermoelectric material and its preparation process

Abstract

The invention relates to a P-type Cu with excessive copper 3.9 Ga 4.2 Te 8 Based medium temperature thermoelectric material and its preparation process, the key points of its design are in Cu 3.8 Ga 4.2 Te 8 In the solid solution, the mole fraction of Cu is increased from the original 0.2375 to 0.2422, and the chemical formula is Cu 3.9 Ga 4.2 Te 8 The thermoelectric material; its preparation process is: according to the chemical formula, weigh the corresponding amount of Cu, Ga, Te three elements, vacuum melting at 950 ° C for 24 hours, after melting and synthesis, cool to 523 ° C and anneal for 72 hours, the ingot after annealing After cooling to room temperature, the ingot is taken out and pulverized into a ball mill. The powder after ball milling is formed by spark plasma sintering in a short period of time. The sintering time is 8 minutes, the sintering temperature is 750°C, and the sintering pressure is 65Mpa to prepare Cu 3.9 Ga 4.2 Te 8 thermoelectric materials. The thermoelectric material is at 775.82K, the Seebeck coefficient α=227.53 (μV / K), and the conductivity σ=6.25×10 3 Ω ‑ 1 .m ‑1 , thermal conductivity κ=0.16(W.K ‑1 .m ‑1 ), the maximum thermoelectric figure of merit ZT=1.57. The material has no pollution, no noise, and has the advantages of reliable operation, long service life and simple preparation process.

Description

technical field [0001] The invention relates to the field of new materials, and is suitable for the key components of medium and high temperature power generation materials for direct conversion of heat energy and electric energy. It is a P-type Cu with excessive copper 3.9 Ga 4.2 Te 8 Based medium temperature thermoelectric material and its preparation process. Background technique [0002] Thermoelectric semiconductor material is a new type of semiconductor functional material that realizes direct mutual conversion of electric energy and thermal energy through the movement of carriers, including electrons or holes. Power generation and refrigeration devices made of thermoelectric materials have the advantages of small size, no pollution, no noise, no wear, good reliability, and long life. In the civilian field, the potential application range: household refrigerators, freezers, superconducting electronic device cooling and waste heat power generation, waste heat utiliza...

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Problems solved by technology

[0004] In order to overcome the problem of insufficient performance of wide-bandgap Cu-Ga-Te ternary semiconductors, the present invention aims to provide a kind of P-type Cu with higher performance to the art. 3.9 Ga 4.2 Te 8 Based on medium-temperature thermoelectric materials and their preparation process, it can solve the technical problems of poor thermoelectric performance of existing similar materials

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