Fig. 2: Structure and characterization of two-dimensional hybrid double perovskites (2D HDPs).
From: Dimensional reduction in Cs2AgBiBr6 enables long-term stable Perovskite-based gas sensing
a Schematic diagram of the 2D HDPs structure. The yellow, green, and pink balls refer to Bi, Ag, and Br atoms, respectively. b–d Representative scanning electron microscopy (SEM) images of (BA)4AgBiBr8, (HA)4AgBiBr8, and (OA)4AgBiBr8 from three independently prepared samples (n = 3), showing similar morphological features. e–g High-resolution transmission electron microscopy (HRTEM) diffraction patterns of the corresponding samples. h Powder X-ray diffraction (PXRD) spectra. i Raman shift spectra. j Ultraviolet–visible (UV–vis) absorption spectra. k Tauc plot of (Aℎν)1/2 versus photon energy (ℎν) for Cs2AgBiBr6 and (BA/HA/OA)4AgBiBr8 Here, A is the absorption coefficient and ℎν is the photon energy in eV. The linear region was extrapolated to estimate the optical band gap. l–n Attenuated total reflection Fourier transform infrared (ATR-FTIR) spectra of (BA)4AgBiBr8, (HA)4AgBiBr8, and (OA)4AgBiBr8. Source data are provided as a Source Data file.
