Figure 1

Characterization of as-grown MAPbI₃ bulk single crystal.

(a) Photograph of a MAPbI₃ bulk single crystal grown through the BSSG method. Natural facets of the MAPbI₃ bulk single crystal were indexed. The unit length of each grid on the coordinate paper is 1 mm. (b) XRD patterns of the rhombic (red) and the parallelogram (blue) natural crystallographic facets of a MAPbI₃ single crystal. The calculated powder XRD pattern (black) is also shown as a reference. The inset shows the details of distinguishing (100) and (112) facets. (c) Drawing of the structure of (100) facet-oriented MAPbI₃ crystal (partial N atoms are made invisible in order to expose the C atoms). (d) UV-visible absorption spectrum for a (100)-cut 1 mm-thick MAPbI₃ single crystal plate.