Method of fabricating thermoelectric material and thermoelectric material fabricated thereby
View Patent ↗The object of the present invention is to provide a method of fabricating a thermoelectric material and a thermoelectric material fabricated thereby. According to the present invention, since carbon nanotubes with no surface treatment are dispersed in the alloy, electrical resistivity decreases and electrical conductivity increases in comparison to surface-treated carbon nanotubes and an amount of thermal conductivity decreased is the same as that in the case of using surface-treated carbon nanotubes, and thus, a ZT value, a thermoelectric figure of merit, is improved. A separate reducing agent is not used and an organic solvent having reducing powder is used to improve economic factors related to material costs and process steps, and carbon nanotubes may be dispersed in the thermoelectric material without mechanical milling.
1. A method of fabricating a thermoelectric material, the method comprising:
preparing a colloidal solution having carbon nanotubes dispersed therein (step 1);
adding a metal salt having thermoelectric properties to the colloidal solution prepared in step 1 (step 2);
precipitating and growing an alloy on outer surfaces of the carbon nanotubes from the metal salt by a chemical reaction of the solution having the metal salt added thereto (step 3),
wherein the carbon nanotubes with no surface treatment are used,
wherein step 1 is performed by introducing carbon nanotubes with a surfactant into 1-dodecanethiol having reducing power, and
wherein the chemical reaction in step 3 is performed at a temperature ranging from 100° C. to 150° C. for 1 hour to 3 hours.
2. The method as set forth in claim 1 , wherein the carbon nanotubes are multi-walled carbon nanotubes.
3. The method as set forth in claim 1 , wherein the surfactant is one selected from the group consisting of oleylamine, trioctylphosphine (TOP), and oleic acid.
4. The method as set forth in claim 1 , wherein the metal salt in step 2 comprises one or more selected from the group consisting of bismuth (Bi) acetate, Bi chloride, and BiNO 3 , and tellurium (Te) chloride.
5. The method as set forth in claim 1 , wherein antimony chloride or selenium chloride is further added to the colloidal solution in step 2.
6. The method as set forth in claim 1 , wherein an inner surface of the carbon nanotubes is free of the alloy.