10.1021/jacs.9b06055.s001
Daniel
B. Straus
Daniel
B.
Straus
Shu Guo
Shu
Guo
Robert J. Cava
Robert J.
Cava
Kinetically
Stable Single Crystals of Perovskite-Phase
CsPbI<sub>3</sub>
American Chemical Society
2019
γ- CsPbI 3
film γ- CsPbI 3
Kinetically Stable Single Crystals
GdFeO 3 structure
Bulk γ- CsPbI 3
powder X-ray diffraction measurements
Single crystal X-ray diffraction characterization
perovskite-phase CsPbI 3
non-perovskite δ- CsPbI 3
Perovskite-Phase CsPbI 3
bulk γ- CsPbI 3
room temperature
2019-07-08 00:00:00
Journal contribution
https://acs.figshare.com/articles/journal_contribution/Kinetically_Stable_Single_Crystals_of_Perovskite-Phase_CsPbI_sub_3_sub_/8859041
We use a solid-state method
to synthesize single crystals
of perovskite-phase cesium lead iodide (γ-CsPbI<sub>3</sub>)
that are kinetically stable at room temperature. Single crystal X-ray
diffraction characterization shows the compound is orthorhombic with
the GdFeO<sub>3</sub> structure at room temperature. Unlike conventional
semiconductors, the optical absorption and joint density-of-states
of bulk γ-CsPbI<sub>3</sub> is greatest near the band edge and
decreases beyond the <i>E</i><sub>g</sub> for at least 1.9
eV. Bulk γ-CsPbI<sub>3</sub> does not show an excitonic resonance
and has an optical band gap of 1.63(3) eV, ∼90 meV smaller
than has been reported in thin films; these and other differences
indicate that previously measured thin film γ-CsPbI<sub>3</sub> shows signatures of quantum confinement. By flowing gases <i>in situ</i> during powder X-ray diffraction measurements, we
confirm that γ-CsPbI<sub>3</sub> is stable to oxygen but rapidly
and catalytically converts to non-perovskite δ-CsPbI<sub>3</sub> in the presence of moisture. Our results provide vital parameters
for theoretical and experimental investigations into perovskite-phase
CsPbI<sub>3</sub> that will the guide the design and synthesis of
atmospherically stable inorganic halide perovskites.