| Autor: |
Wang, Xinwei, Kavanagh, Sean R., Scanlon, David O., Walsh, Aron |
| Rok vydání: |
2023 |
| Předmět: |
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| Zdroj: |
Phys. Rev. B 2023, 108, 134102 |
| Druh dokumentu: |
Working Paper |
| DOI: |
10.1103/PhysRevB.108.134102 |
| Popis: |
The phenomenon of negative-U behavior, where a defect traps a second charge carrier more strongly than the first, has been established in many host crystals. Here we report the case of four-carrier transitions for both vacancy defects in Sb2Se3. A global structure searching strategy is employed to explore the defect energy landscape from first-principles, revealing previously-unrealized configurations which facilitate a major charge redistribution. Thermodynamic analysis of the accessible charge states reveals a four-electron negative-U transition (delta q = 4) for both V_Se and V_Sb and, by consequence, amphoteric behavior for all intrinsic defects in Sb2Se3, with impact on its usage in solar cells. To the best of our knowledge, four-electron negative-U behavior has not been previously explored in this or other compounds. The unusual behavior is facilitated by valence alternation, a reconfiguration of the local bonding environments, characteristic of both Se and Sb. |
| Databáze: |
arXiv |
| Externí odkaz: |
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