First-Principles Investigation into the Interaction of H<sub>2</sub>O with α-CsPbI<sub>3</sub> and the Intrinsic Defects within It
CsPbI<sub>3</sub> possesses three photoactive black phases (α, β, and γ) with perovskite structures and a non-photoactive yellow phase (δ) without a perovskite structure. Among these, α-CsPbI<sub>3</sub> exhibits the best performance. However, it only exists at high temperatu...
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MDPI AG
2024-02-01
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| Online Access: | https://www.mdpi.com/1996-1944/17/5/1091 |
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| author | Na Wang Yaqiong Wu |
| author_facet | Na Wang Yaqiong Wu |
| author_sort | Na Wang |
| collection | DOAJ |
| description | CsPbI<sub>3</sub> possesses three photoactive black phases (α, β, and γ) with perovskite structures and a non-photoactive yellow phase (δ) without a perovskite structure. Among these, α-CsPbI<sub>3</sub> exhibits the best performance. However, it only exists at high temperatures and it tends to transform into the δ phase at room temperature, especially in humid environments. Therefore, the phase stability of CsPbI<sub>3</sub>, especially in humid environments, is the main obstacle to its further development. In this study, we studied the interaction of H<sub>2</sub>O with α-CsPbI<sub>3</sub> and the intrinsic defects within it. It was found that the adsorption energy in the bulk is higher than that on the surface (−1.26 eV in the bulk in comparison with −0.60 eV on the surface); thus, H<sub>2</sub>O is expected to have a tendency to diffuse into the bulk once it adsorbs on the surface. Moreover, the intrinsic vacancy of V<sub>Pb</sub><sup>0</sup> in the bulk phase can greatly promote H<sub>2</sub>O insertion due to the rearrangement of two I atoms in the two PbI<sub>6</sub> octahedrons nearest to V<sub>Pb</sub><sup>0</sup> and the resultant breaking of the Pb–I bond, which could promote the phase transition of α-CsPbI<sub>3</sub> in a humid environment. Moreover, H<sub>2</sub>O adsorption onto V<sub>I</sub><sup>+1</sup> contributes to a further distortion in the vicinity of V<sub>I</sub><sup>+1</sup>, which is expected to enhance the effect of V<sub>I</sub><sup>+1</sup> on the phase transition of α-CsPbI<sub>3</sub>. Clarifying the interaction of H<sub>2</sub>O with α-CsPbI<sub>3</sub> and the intrinsic defects within it may provide guidance for further improvements in the stability of α-CsPbI<sub>3</sub>, especially in humid environments. |
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| issn | 1996-1944 |
| language | English |
| last_indexed | 2024-04-25T00:25:34Z |
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| spelling | doaj.art-7a2b77d4185a477fac4b555413b3fa672024-03-12T16:49:14ZengMDPI AGMaterials1996-19442024-02-01175109110.3390/ma17051091First-Principles Investigation into the Interaction of H<sub>2</sub>O with α-CsPbI<sub>3</sub> and the Intrinsic Defects within ItNa Wang0Yaqiong Wu1Department of Physical Chemistry, University of Science and Technology Beijing, Beijing 100083, ChinaDepartment of Physical Chemistry, University of Science and Technology Beijing, Beijing 100083, ChinaCsPbI<sub>3</sub> possesses three photoactive black phases (α, β, and γ) with perovskite structures and a non-photoactive yellow phase (δ) without a perovskite structure. Among these, α-CsPbI<sub>3</sub> exhibits the best performance. However, it only exists at high temperatures and it tends to transform into the δ phase at room temperature, especially in humid environments. Therefore, the phase stability of CsPbI<sub>3</sub>, especially in humid environments, is the main obstacle to its further development. In this study, we studied the interaction of H<sub>2</sub>O with α-CsPbI<sub>3</sub> and the intrinsic defects within it. It was found that the adsorption energy in the bulk is higher than that on the surface (−1.26 eV in the bulk in comparison with −0.60 eV on the surface); thus, H<sub>2</sub>O is expected to have a tendency to diffuse into the bulk once it adsorbs on the surface. Moreover, the intrinsic vacancy of V<sub>Pb</sub><sup>0</sup> in the bulk phase can greatly promote H<sub>2</sub>O insertion due to the rearrangement of two I atoms in the two PbI<sub>6</sub> octahedrons nearest to V<sub>Pb</sub><sup>0</sup> and the resultant breaking of the Pb–I bond, which could promote the phase transition of α-CsPbI<sub>3</sub> in a humid environment. Moreover, H<sub>2</sub>O adsorption onto V<sub>I</sub><sup>+1</sup> contributes to a further distortion in the vicinity of V<sub>I</sub><sup>+1</sup>, which is expected to enhance the effect of V<sub>I</sub><sup>+1</sup> on the phase transition of α-CsPbI<sub>3</sub>. Clarifying the interaction of H<sub>2</sub>O with α-CsPbI<sub>3</sub> and the intrinsic defects within it may provide guidance for further improvements in the stability of α-CsPbI<sub>3</sub>, especially in humid environments.https://www.mdpi.com/1996-1944/17/5/1091CsPbI<sub>3</sub>H<sub>2</sub>Ovacancybinding energystability |
| spellingShingle | Na Wang Yaqiong Wu First-Principles Investigation into the Interaction of H<sub>2</sub>O with α-CsPbI<sub>3</sub> and the Intrinsic Defects within It Materials CsPbI<sub>3</sub> H<sub>2</sub>O vacancy binding energy stability |
| title | First-Principles Investigation into the Interaction of H<sub>2</sub>O with α-CsPbI<sub>3</sub> and the Intrinsic Defects within It |
| title_full | First-Principles Investigation into the Interaction of H<sub>2</sub>O with α-CsPbI<sub>3</sub> and the Intrinsic Defects within It |
| title_fullStr | First-Principles Investigation into the Interaction of H<sub>2</sub>O with α-CsPbI<sub>3</sub> and the Intrinsic Defects within It |
| title_full_unstemmed | First-Principles Investigation into the Interaction of H<sub>2</sub>O with α-CsPbI<sub>3</sub> and the Intrinsic Defects within It |
| title_short | First-Principles Investigation into the Interaction of H<sub>2</sub>O with α-CsPbI<sub>3</sub> and the Intrinsic Defects within It |
| title_sort | first principles investigation into the interaction of h sub 2 sub o with α cspbi sub 3 sub and the intrinsic defects within it |
| topic | CsPbI<sub>3</sub> H<sub>2</sub>O vacancy binding energy stability |
| url | https://www.mdpi.com/1996-1944/17/5/1091 |
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