Journal: Journal of the American Chemical Society

Article Title: Structural Rigidity Enables Amplified Spontaneous Emission in 2D Alkylammonium Tin Perovskites

doi: 10.1021/jacs.6c14883

Figure Lengend Snippet: Crystal structures from single-crystal X-ray diffraction showing the low- and high-temperature phases of (a) BA 2 SnI 4 at 125 K (structural data from ref ) and 296 K and of (b) DABSnI 4 at 100 and 296 K, determined in this work. Evolution of structural parameters determined from single-crystal XRD structures: (c) interplanar distances between inorganic layers (measured as the distance between iodides in the apical position), (d) in-plan tilt angle (D in ), the out-of-plane tilt angle (D out ), octahedral tilting (D tilt ), and (e) quadratic elongation. See Table S3 for additional details. The structural parameters for BA 2 SnI 4 at 125 K are calculated from the crystal structures reported in ref . Temperature-dependent low-energy Raman spectra of (f) BA 2 SnI 4 measured with a 785 nm laser, with a cutoff filter at 50 cm –1 (after 230 cm –1 , the wavenumbers are multiplied by a factor of 5 for clarity), and (g) DABSnI 4 , measured with 647.1 nm laser excitation. The main spectral changes occurring at the phase transitions are highlighted in the insets.

Article Snippet: The Raman spectra of BA 2 SnI 4 were acquired with a confocal Raman microscope (Horiba Xplora Plus, Horiba) equipped with edge filters enabling measurements as close as 50 cm –1 to the Rayleigh line.

Techniques: Phase Transitions