Fig. 2
From: Dimensionality engineering of hybrid halide perovskite light absorbers
Cation dependence of the crystal structure of perovskite and the quantum confinement effect. a 3D networks of CH3NH3PbI3; b 1D chains of CH3CH2NH3PbI3; c 1D chain-structure of CH3(CH2)2NH3PbI3; d 2D layer-structure of CH3(CH2)3NH3PbI3. e Schematic MDP structure and possible energy-level schemes that can arise within these structures, where semiconducting inorganic sheets alternate with organic layers having much wider bandgaps, resulting in a Type I quantum well structure. UV−visible absorption spectra or Tauc plot of f MAPbI3, EAPbI3, and PAPbI3 (Reproduced with permission from ref. 88); g (BA)2(MA)n−1PbnI3n+1 perovskites (for n =1, 2, 3, 4, ∞) (Reproduced with permission from ref. 13)
