Characterizing composition and crystallography of a mixed halide perovskite in the SEM

Instruments used

EDAX^® Clarity™ Super electron backscatter diffraction (EBSD) and OnPoint™ backscattered electron (BSE) detectors with unparalleled performance for analyzing beam-sensitive samples.

Background

All-inorganic perovskites such as cesium halide have aroused great interest as highly efficient solar cells and light-emitting diodes due to their outstanding photoelectric and optoelectronic properties, and low cost of manufacture. Commonly, cesium halide perovskites are found in the compositional forms CsPb(Br_xI_1-x)₃ or Cs₄Pb(Br_xI_1-x)₆ (0 < x < 1); however, each composition can exist in several different crystal structures and with varying Br/I ratios both of which have a strong influence on a device’s grain structure, optical properties, and photovoltaic performance. For the development of improved devices, it is important that the morphology, crystal structure, and composition of these materials can be characterized. However, routine determination of their composition and crystallography remains elusive due to the small crystal size and fragility of the crystal structure under electron irradiation.