Structural Stability, Vibrational Properties, and Photoluminescence in CsSnI3 Perovskite upon the Addition of SnF2

详细信息    查看全文

• 作者：Athanassios G. Kontos ; Andreas KaltzoglouEirini Siranidi ; Dimitrios Palles ; Giasemi K. Angeli ; Michalis K. Arfanis ; Vassilis Psycharis ; Yannis S. Raptis ; Efstratios I. Kamitsos ; Pantelis N. Trikalitis ; Constantinos C. Stoumpos ; Mercouri G. KanatzidisPolycarpos Falaras
• 刊名：Inorganic Chemistry
• 出版年：2017
• 出版时间：January 3, 2017
• 年：2017
• 卷：56
• 期：1
• 页码：84-91
• 全文大小：513K
• ISSN：1520-510X

文摘

The CsSnI₃ perovskite and the corresponding SnF₂-containing material with nominal composition CsSnI_2.95F_0.05 were synthesized by solid-state reactions and structurally characterized by powder X-ray diffraction. Both materials undergo rapid phase transformation upon exposure to air from the black orthorhombic phase (B-γ-CsSnI₃) to the yellow orthorhombic phase (Y-CsSnI₃), followed by irreversible oxidation into Cs₂SnI₆ within several hours. The phase transition occurs at a significantly lower rate in the SnF₂-containing material rather than in the pure perovskite. The high hole-carrier concentration of the materials prohibits the detection of Raman signals for B-γ-CsSnI₃ and induces a very strong plasmonic reflectance in the far-IR. In contrast, far-IR phonon bands and a rich Raman spectrum are observed for the Y-CsSnI₃ modification below 140 cm^–1 with weak frequency shift gradients versus temperatures between −95 and +170 °C. Above 170 °C, the signal is lost due to B-α-CsSnI₃ re-formation. The photoluminescence spectra exhibit residual blue shifts and broadening as a sign of structural transformation initiation.