THERMOELECTRIC FIGURE OF MERIT ENHANCEMENT BY MODIFICATION OF THE ELECTRONIC DENSITY OF STATES
A thermoelectric material and a method of using a thermoelectric material is provided. The thermoelectric material can include at least one compound. For example, the at least one compound may be a Group IV-VI compound such as lead telluride. The at least one compound may further include one or more dopants such as sodium, potassium, and thallium. The method of using a thermoelectric material can include exposing at least one portion of the at least one compound to a temperature greater than about 700 K.
1 . A thermoelectric material comprising at least one compound having a general composition of A w-t Te 1-r E r D t , wherein w>t, 0<r≦0.30, 0<t≦0.05, wherein A is selected from the group consisting of lead and tin, Te is tellurium, D is selected from the group consisting of sodium, potassium, thallium, and E is selected from the group consisting of sulfur and selenium.
2 . The thermoelectric material of claim 1 , wherein 0.08≦r≦0.12.
3 . The thermoelectric material of claim 1 , wherein 0.01≦t≦0.03.
4 . The thermoelectric material of claim 1 , wherein 0.94≦w≦1.06.
5 . The thermoelectric material of claim 1 , wherein the at least one compound is p-type.
6 . The thermoelectric material of claim 1 , wherein D comprises thallium.
7 . The thermoelectric material of claim 6 , wherein E comprises sulfur.
8 . The thermoelectric material of claim 1 , wherein D comprises sodium.
9 . The thermoelectric material of claim 8 , wherein E comprises sulfur.
10 . The thermoelectric material of claim 1 , wherein D comprises potassium.
11 . The thermoelectric material of claim 10 , wherein E comprises sulfur.
12 . The thermoelectric material of claim 1 , wherein A comprises tin.
13 . The thermoelectric material of claim 12 , wherein D comprises indium.
14 . The thermoelectric material of claim 13 , wherein E comprises selenium.
15 . A thermoelectric material comprising at least one compound having a general composition of A w-t Te 1 D t , wherein w>t, 0<t≦0.05, wherein A is selected from the group consisting of lead and tin, Te is tellurium, and D consists of sodium and potassium.
16 . The thermoelectric material of claim 15 , wherein 0.01≦t≦0.03.
17 . The thermoelectric material of claim 15 , wherein at least 10 atomic % of D is sodium and at least 10 atomic % of D is potassium.
18 . The thermoelectric material of claim 15 , wherein 0.94≦w≦1.06.
19 . The thermoelectric material of claim 15 , wherein the at least one compound is p-type.
20 . The thermoelectric material of claim 15 , wherein the at least one compound further comprises thallium.
21 . A method of using a thermoelectric material comprising:
providing a thermoelectric material comprising at least one compound having a general composition of A w-t Te 1 D t , wherein w>t, 0<t≦0.05, wherein A is selected from the group consisting of lead and tin, Te is tellurium, and D consists of sodium and thallium; and
exposing at least one portion of the at least one compound to a temperature greater than about 550 K during use of the thermoelectric material.
22 . The method of claim 21 , wherein 0.01≦t≦0.03.
23 . The method of claim 21 , wherein the at least one compound further comprises potassium.
24 . The method of claim 21 , wherein the at least one portion of the at least one compound is exposed to a temperature greater than about 700 K during use of the thermoelectric material.
25 . The method of claim 21 , wherein the at least one compound comprises a thermoelectric figure of merit greater than 1 at temperatures between about 550 K and about 700 K.
26 . A method of using a thermoelectric material comprising:
providing a thermoelectric material comprising at least one compound having a general composition of A w-t Te 1 D t , wherein w>t, 0<t≦0.05, wherein A is selected from the group consisting of lead and tin, Te is tellurium, and D consists of indium; and
exposing at least one portion of the at least one compound to a temperature greater than about 550 K during use of the thermoelectric material.
27 . The method of claim 26 , wherein 0.01≦t≦0.03.
28 . The method of claim 26 , wherein the at least one compound further comprises selenium.
29 . The method of claim 28 , wherein a concentration of the selenium is between about 0.5 and about 5 atomic percent of the at least one compound.
30 . The method of claim 26 , wherein A consists essentially of tin.