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Phase Boundary Mapping of Tin‐Doped ZnSb Reveals Thermodynamic Route to High Thermoelectric Efficiency
Author(s) -
Wood Maxwell,
Toriyama Michael Y.,
Dugar Shristi,
Male James,
Anand Shashwat,
Stevanović Vladan,
Snyder G. Jeffrey
Publication year - 2021
Publication title -
advanced energy materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.08
H-Index - 220
eISSN - 1614-6840
pISSN - 1614-6832
DOI - 10.1002/aenm.202100181
Subject(s) - materials science , thermoelectric effect , doping , phase diagram , tin , thermoelectric materials , phase boundary , ternary operation , figure of merit , phase (matter) , condensed matter physics , nanotechnology , optoelectronics , analytical chemistry (journal) , thermodynamics , metallurgy , chemistry , physics , organic chemistry , chromatography , computer science , programming language
Abstract 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 × 10 19 cm −3 when the material is in equilibrium with Zn 4 Sb 3 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.