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Title: Enhancement of thermoelectric performance in n-type PbTe1-ySey by doping Cr and tuning Te:Se ratio

Lead telluride and its alloys have been extensively studied for medium temperature thermoelectric applications due to decent figure-of-merit (ZT) at temperature close to 900 K. However, little emphasis has been given to improve the ZT near room temperature. In this investigation, we report a systematic study of Cr doping in PbTe1-ySey with y=0, 0.25, 0.5, 0.75, 0.85, and 1. We found the peak ZT temperature increased with increasing concentration of Se. The highest ZT of ~0.6 at room temperature in Te-rich Cr0.015Pb0.985Te0.75Se0.25 was obtained due to a lowered thermal conductivity and enhanced power factor resulted from high Seebeck coefficient of about -220 µV K-1 and high Hall mobility ~1120 cm2 V-1 s-1 at room temperature. A room temperature ZT of ~0.5 and peak ZT of ~1 at about 573–673 K is shown by Se-rich sample Cr0.01Pb0.99Te0.25Se0.75. This improvement of the room temperature ZTimproved the average ZT over a wide temperature range and could potentially lead to a single leg efficiency of thermoelectric conversion for Te-rich Cr0.015Pb0.985Te0.75Se0.25 up to ~11% and Se-rich Cr0.01Pb0.99Te0.25Se0.75 up to ~13% with cold side and hot side temperature at 300 K and 873 K, respectively, if matched with appropriate p-type legs.
 [1] ;  [1] ;  [2] ;  [3] ;  [1] ;  [1] ;  [1] ;  [3] ;  [2] ;  [1]
  1. Univ. of Houston, TX (United States)
  2. MIT (Massachusetts Inst. of Technology), Cambridge, MA (United States)
  3. Boston College, Chestnut Hill, MA (United States)
Publication Date:
OSTI Identifier:
DOE Contract Number:
SC0001299; FG02-09ER46577
Resource Type:
Journal Article
Resource Relation:
Journal Name: Nano Energy; Journal Volume: 13; Related Information: S3TEC partners with Massachusetts Institute of Technology (lead); Boston College; Oak Ridge National Laboratory; Rensselaer Polytechnic Institute
Research Org:
Energy Frontier Research Centers (EFRC); Solid-State Solar-Thermal Energy Conversion Center (S3TEC)
Sponsoring Org:
USDOE SC Office of Basic Energy Sciences (SC-22)
Country of Publication:
United States
solar (photovoltaic), solar (thermal), solid state lighting, phonons, thermal conductivity, thermoelectric, defects, mechanical behavior, charge transport, spin dynamics, materials and chemistry by design, optics, synthesis (novel materials), synthesis (self-assembly), synthesis (scalable processing)