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Title: A simple chemical guide for finding novel n-type dopable Zintl pnictide thermoelectric materials
Computations have predicted good thermoelectric performance for a number of Zintl phases when doped n-type. Combined with the successful experimental realization of n-type KGaSb 4 , KAlSb 4 , and Mg 3 Sb 2 with zT ≳ 1, this has fueled efforts to discover novel n-type dopable Zintl phases. However, a majority of Zintl phases exhibit strong proclivity toward p-type doping and prior successes in finding n-type dopable Zintls were largely serendipitous. Herein we use modern first-principles defect calculations to study trends in the dopability of Zintl pnictides and find that the average oxidation state of the anion is a useful chemical guide to identify novel n-type dopable phases. Specifically, we observe that Zintl pnictides with average oxidation of the anion near −1 are n-type dopable. The trend is mainly a consequence of the high formation energy of native acceptor defects ( e.g. cation vacancies) and the resulting absence of charge (electron) compensation. Using the oxidation state guide in conjunction with a descriptor of thermoelectric performance, we conduct a large-scale materials search and identify promising candidates that are n-type dopable.  more » « less
Award ID(s):
1729594
NSF-PAR ID:
10122569
Author(s) / Creator(s):
; ; ;
Date Published:
Journal Name:
Journal of Materials Chemistry A
Volume:
7
Issue:
33
ISSN:
2050-7488
Page Range / eLocation ID:
19385 to 19395
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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