TY - JOUR
T1 - Phase Boundary Mapping of Tin-Doped ZnSb Reveals Thermodynamic Route to High Thermoelectric Efficiency
AU - Wood, Maxwell
AU - Toriyama, Michael Y.
AU - Dugar, Shristi
AU - Male, James
AU - Anand, Shashwat
AU - Stevanović, Vladan
AU - Snyder, G. Jeffrey
N1 - Funding Information:
M.W., M.Y.T., and S.D. contributed equally to this work. The authors thank Dr. Anuj Goyal for computational assistance regarding GW band edge shifts of ZnSb. The authors acknowledge the NSF DMREF award #1729487. M.Y.T. acknowledges support from the U.S. Department of Energy through the Computational Science Graduate Fellowship (DOE CSGF) under Grant Number DE‐SC0020347. This research was supported in part through the computational resources and staff contributions provided for the Quest high performance computing facility at Northwestern University, which is jointly supported by the Office of the Provost, the Office for Research, and Northwestern University Information Technology. The authors acknowledge support from the NASA Science Mission Directorate's Radioisotope Power Systems Thermoelectric Technology Development program. M.W.'s research at the Jet Propulsion Laboratory was supported by an appointment to the NASA Postdoctoral Program, administered by the Universities Space Research Association under contract with the NASA. This work was performed under the following financial assistance award 70NANB19H005 from U.S. Department of Commerce, National Institute of Standards and Technology as part of the Center for Hierarchical Materials Design (CHiMaD).
Publisher Copyright:
© 2021 Wiley-VCH GmbH
PY - 2021/5/27
Y1 - 2021/5/27
N2 - The thermoelectric material ZnSb utilizes elements that are inexpensive, abundant, and viable for mass production. While a high thermoelectric figure of merit zT, is difficult to achieve in Sn-doped ZnSb, it is shown that this obstacle is primarily due to shortcomings in reaching high enough carrier concentrations. Sn-doped samples prepared in different equilibrium phase spaces in the ternary Zn-Sb-Sn system are investigated using phase boundary mapping, and a range of achievable carrier concentrations is found in the doped samples. The sample with the highest zT in this study, which is obtained with a carrier concentration of 2 × 1019 cm−3 when the material is in equilibrium with Zn4Sb3 and Sn, confirms that the doping efficiency can be controlled by preparing the doped sample in a particular region of the thermodynamic phase diagram. Moreover, density functional theory calculations suggest that the doping efficiency is limited by the solubility of Sn in ZnSb, as opposed to compensation from native defects. Cognizance of thermodynamic conditions is therefore crucial for rationally tuning the carrier concentration, a quantity that is significant for many areas of semiconductor technologies.
AB - The thermoelectric material ZnSb utilizes elements that are inexpensive, abundant, and viable for mass production. While a high thermoelectric figure of merit zT, is difficult to achieve in Sn-doped ZnSb, it is shown that this obstacle is primarily due to shortcomings in reaching high enough carrier concentrations. Sn-doped samples prepared in different equilibrium phase spaces in the ternary Zn-Sb-Sn system are investigated using phase boundary mapping, and a range of achievable carrier concentrations is found in the doped samples. The sample with the highest zT in this study, which is obtained with a carrier concentration of 2 × 1019 cm−3 when the material is in equilibrium with Zn4Sb3 and Sn, confirms that the doping efficiency can be controlled by preparing the doped sample in a particular region of the thermodynamic phase diagram. Moreover, density functional theory calculations suggest that the doping efficiency is limited by the solubility of Sn in ZnSb, as opposed to compensation from native defects. Cognizance of thermodynamic conditions is therefore crucial for rationally tuning the carrier concentration, a quantity that is significant for many areas of semiconductor technologies.
KW - ZnSb
KW - defect calculations
KW - dopability
KW - phase-boundary mapping
KW - thermoelectric
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U2 - 10.1002/aenm.202100181
DO - 10.1002/aenm.202100181
M3 - Article
AN - SCOPUS:85104242992
VL - 11
JO - Advanced Energy Materials
JF - Advanced Energy Materials
SN - 1614-6832
IS - 20
M1 - 2100181
ER -
