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arXiv · 1112.4840

Comment on "Uncovering the Complex Behavior of Hydrogen in Cu2O"

K. Biswas·M. -H. Du·J. T. -Thienprasert·S. Limpijumnong·D. J. Singh
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Abstract

In a recent Letter Scanlon and Watson reported their first principles results on hydrogen in Cu2O. Their main conclusions are: (1) an interstitial H in Cu2O prefers to occupy the tetrahedral site, which is coordinated with four Cu cations, in all three charge states (+1, neutral, and -1); (2) H will bind with a Cu vacancy and form an electrically active H-VCu defect complex, which is amphoteric with (+/0) and (0/-)transition levels at Ev + 0.1 and Ev + 1.1 eV, respectively. However, these two conclusions contradict two generally observed behaviors of H in oxides: (i) cationic H usually binds with an O atom, forming a single O-H bond, while the anionic H usually binds with cations with multi-coordination; (ii) H usually passivates cation vacancies in oxides. In this Comment, we explicitly show that with charge state +1, H prefers to bind with a single O anion rather than with four Cu cations and that H-VCu does not induce any defect levels inside the band gap.

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K. Biswas, M. -H. Du, J. T. -Thienprasert, S. Limpijumnong, D. J. Singh. 2011-12-20. Comment on "Uncovering the Complex Behavior of Hydrogen in Cu2O". https://arxiv.org/abs/1112.4840

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