Passivating Grain Boundaries in Polycrystalline CdTe

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Abstract

Using first-principles density functional calculations, we investigate the structure and properties of three different grain boundaries (GBs) in the solar absorber material CdTe. Among the low ∑ value symmetric tilt GBs ∑3 (111), ∑3 (112), and ∑5 (310), we confirm that the ∑3 (111) is the most stable one but is relatively benign for carrier transport as it does not introduce any new states into the gap. The ∑3 (112) and ∑5 (310) GBs, however, are detrimental due to gap states induced by Te–Te and Cd–Cd dangling bonds. We systematically investigate the segregation of O, Se, Cl, Na, and Cu to the GBs and associated electronic properties. Our results show that co-doping with Cl and Na is predicted to be a viable approach passivating all gap states induced by dangling bonds in CdTe.
Original languageEnglish
Pages (from-to)23882-23889
Number of pages8
JournalJournal of Physical Chemistry C
Volume123
Issue number39
Early online date12 Sept 2019
DOIs
Publication statusPublished - 3 Oct 2019

Bibliographical note

© 2019 American Chemical Society

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