Figure 8.

a) Crystal structure of 0D Cs₃Sb₂I₉. Reproduced with permission.^{[ 157 ]} Copyright 2016, American Chemical Society. b) Crystal structure of 2D Cs₃Sb₂I₉. c) XRD of Cs₃Sb₂I₉ nanoplates with periodic angle intervals. Reproduced with permission.^{[ 96 ]} Copyright 2017, Wiley‐VCH. d) UV−vis absorption and PL spectra of Cs₃Sb₂Br₉ nanocrystals. Inset: image of a colloidal Cs₃Sb₂Br₉ QD solution under the excitation of 365 nm. e) Absorption and PL spectra of Cs₃Sb₂X₉ NCs via halide substitution. Reproduced with permission.^{[ 80 ]} Copyright 2017, American Chemical Society. f) Normalized PL spectra of Cs₃Sb₂X₉ (X = Cl, Br, I) thin films. g) Broad emission model of Cs₃Sb₂X₉ (X = Cl, Br, I) thin films with nonradiative recombination due to phonons. Reproduced with permission.^{[ 156 ]} Copyright 2019, American Chemical Society. h) Excitation and emission spectra of bulk crystals (Ph₄P)₂SbCl₅. Inset: typical optical images of bulk (Ph₄P)₂SbCl₅ crystals without and with 365 nm UV light excitation. Reproduced with permission.^{[ 82 ]} Copyright 2018, American Chemical Society.