Thermoelectric materials and methods for synthesis thereof
Materials having improved thermoelectric properties are disclosed. In some embodiments, lead telluride/selenide based materials with improved figure of merit and mechanical properties are disclosed. In some embodiments, the lead telluride/selenide based materials of the present disclosure are p-type thermoelectric materials formed by adding sodium (Na), silicon (Si) or both to thallium doped lead telluride materials. In some embodiments, the lead telluride/selenide based materials are formed by doping lead telluride/selenides with potassium.
1. A thermoelectric material having a general formula Tl 0.02 Pb 0.98 Te 1-x Se x Si 0.02 Na z , where
x has a value from 0 to 1,
and
z has a value of 0.015, 0.020, or 0.025.
2. The thermoelectric material of claim 1 wherein having a figure of merit of about 1.5 or higher at about 770K.
3. The thermoelectric material of claim 1 having a formula Tl 0.02 Pb 0.98 TeSi 0.02 Na z , where
z has a value of 0.015, 0.020 or 0.025.
4. The thermoelectric material of claim 1 , where x has a value of 0 or 1.
5. A thermoelectric material having a stoichiometric formula Tl 0.02 Pb 0.98 TeSi 0.02 Na 0.02 .
6. A method of synthesis of a thermoelectric material comprising:
generating a plurality of nanoparticles from a starting material comprising lead, tellurium, selenium and one or more dopants selected from the group consisting of sodium, silicon or thallium in sufficient amounts according to a general formula Tl 0.02 Pb 0.98 Te 1-x Se x Si 0.02 Na z , where
x has a value from 0 to 1,
and
z has a value of 0.015, 0.020 or 0.025; and
consolidating the nanoparticles at elevated pressure and temperature.
7. The method of claim 6 wherein the plurality of nanoparticles are generated by ball milling and consolidated by hot pressing.