Fig. 1: Microstructure and electronic structure of (NH4)BiI3 crystals.
From: 2D (NH4)BiI3 enables non-volatile optoelectronic memories for machine learning
a Photograph of (NH4)BiI3 crystals prepared by CVT. Scale bar, 2 cm. b Plan-view HAADF-STEM image of (NH4)BiI3 crystal, showing excellent crystallinity. Scale bar, 1 nm. c Cross-sectional HAADF-STEM image of a multilayer (NH4)BiI3 along [10\(\bar{1}\)0] direction and the corresponding high-resolution EDS mappings of Bi and I elements. Scale bar, 500 pm. d Crystal structure of (NH4)BiI3 identified by DFT calculation. e Experimental and calculated XRD patterns of (NH4)BiI3 powders. f Experimental absorption spectrum of (NH4)BiI3 crystal. g Electronic band structure and DOSs of (NH4)BiI3 calculated using HSE hybrid functional. h Calculated photoconductivity of (NH4)BiI3.
