Abstract
The application of pressure on halide perovskite materials provides key insights into their structural properties and the collective motions of their basic structural units. Here, we use synchrotron X-ray diffraction and Raman spectroscopy measurements combined with density functional theory calculations to perform a comprehensive study on the structural and vibrational properties of the so-called defect halide perovskites Cs2SnX6 (X = Cl, Br, I) under high hydrostatic pressures up to 20 GPa. We find that, while Cs2SnCl6 and Cs2SnBr6 retain a face-centered cubic (FCC) structure for all studied pressures, Cs2SnI6 undergoes successive phase transformations initially to a more disordered structure and secondly to a low-symmetry monoclinic I2/m phase. The first transition is only evidenced by certain features emerging in the Raman spectra at ∼3.3 GPa, whereas the latter happens in a pressure window of around 8-10 GPa and involves tilting and elongation of SnI6 octahedra and hysteretic behavior with pressure release. Overall, the results reveal that pressure can alter significantly the structural characteristics of certain defect perovskites, such as Cs2SnI6, which is also anticipated to affect their optoelectronic properties.
| Original language | English |
|---|---|
| Pages (from-to) | 24004-24013 |
| Number of pages | 10 |
| Journal | Journal of Physical Chemistry C |
| Volume | 122 |
| Issue number | 42 |
| DOIs | |
| Publication status | Published - Oct 25 2018 |
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ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Energy(all)
- Physical and Theoretical Chemistry
- Surfaces, Coatings and Films
Cite this
Defect Perovskites under Pressure : Structural Evolution of Cs2SnX6 (X = Cl, Br, I). / Bounos, Giannis; Karnachoriti, Maria; Kontos, Athanassios G.; Stoumpos, Constantinos C.; Tsetseris, Leonidas; Kaltzoglou, Andreas; Guo, Xiaofeng; Lü, Xujie; Raptis, Yannis S.; Kanatzidis, Mercouri G; Falaras, Polycarpos.
In: Journal of Physical Chemistry C, Vol. 122, No. 42, 25.10.2018, p. 24004-24013.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Defect Perovskites under Pressure
T2 - Structural Evolution of Cs2SnX6 (X = Cl, Br, I)
AU - Bounos, Giannis
AU - Karnachoriti, Maria
AU - Kontos, Athanassios G.
AU - Stoumpos, Constantinos C.
AU - Tsetseris, Leonidas
AU - Kaltzoglou, Andreas
AU - Guo, Xiaofeng
AU - Lü, Xujie
AU - Raptis, Yannis S.
AU - Kanatzidis, Mercouri G
AU - Falaras, Polycarpos
PY - 2018/10/25
Y1 - 2018/10/25
N2 - The application of pressure on halide perovskite materials provides key insights into their structural properties and the collective motions of their basic structural units. Here, we use synchrotron X-ray diffraction and Raman spectroscopy measurements combined with density functional theory calculations to perform a comprehensive study on the structural and vibrational properties of the so-called defect halide perovskites Cs2SnX6 (X = Cl, Br, I) under high hydrostatic pressures up to 20 GPa. We find that, while Cs2SnCl6 and Cs2SnBr6 retain a face-centered cubic (FCC) structure for all studied pressures, Cs2SnI6 undergoes successive phase transformations initially to a more disordered structure and secondly to a low-symmetry monoclinic I2/m phase. The first transition is only evidenced by certain features emerging in the Raman spectra at ∼3.3 GPa, whereas the latter happens in a pressure window of around 8-10 GPa and involves tilting and elongation of SnI6 octahedra and hysteretic behavior with pressure release. Overall, the results reveal that pressure can alter significantly the structural characteristics of certain defect perovskites, such as Cs2SnI6, which is also anticipated to affect their optoelectronic properties.
AB - The application of pressure on halide perovskite materials provides key insights into their structural properties and the collective motions of their basic structural units. Here, we use synchrotron X-ray diffraction and Raman spectroscopy measurements combined with density functional theory calculations to perform a comprehensive study on the structural and vibrational properties of the so-called defect halide perovskites Cs2SnX6 (X = Cl, Br, I) under high hydrostatic pressures up to 20 GPa. We find that, while Cs2SnCl6 and Cs2SnBr6 retain a face-centered cubic (FCC) structure for all studied pressures, Cs2SnI6 undergoes successive phase transformations initially to a more disordered structure and secondly to a low-symmetry monoclinic I2/m phase. The first transition is only evidenced by certain features emerging in the Raman spectra at ∼3.3 GPa, whereas the latter happens in a pressure window of around 8-10 GPa and involves tilting and elongation of SnI6 octahedra and hysteretic behavior with pressure release. Overall, the results reveal that pressure can alter significantly the structural characteristics of certain defect perovskites, such as Cs2SnI6, which is also anticipated to affect their optoelectronic properties.
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U2 - 10.1021/acs.jpcc.8b08449
DO - 10.1021/acs.jpcc.8b08449
M3 - Article
VL - 122
SP - 24004
EP - 24013
JO - Journal of Physical Chemistry C
JF - Journal of Physical Chemistry C
SN - 1932-7447
IS - 42
ER -