Mechano-Chemical Synthesis, Structural Features and Optical Gap of Hybrid CH3NH3CdBr3 Perovskite

Hybrid methyl-ammonium (MA:CH3NH3+) lead halide MAPbX(3) (X = halogen) perovskites exhibit an attractive optoelectronic performance that can be applied to the next generation of solar cells. To extend the field of interest of these hybrid materials, we describe the synthesis by a solvent-free ball-milling procedure, yielding a well crystallized, pure and moisture stable specimen of the Cd tribromide counterpart, MACdBr(3), which contains chains of face-sharing CdBr6 octahedra in a framework defined in the Cmc2(1) (No 36) space group. The details of the structural arrangement at 295 K have been investigated by high angular resolution synchrotron x-ray diffraction (SXRD), including the orientation of the organic MA units, which are roughly aligned along the c direction, given the acentric nature of the space group. UV-vis spectra unveil a gap of 4.6 eV, which could be useful for ultraviolet detectors.

Automated summary

A stable and well-crystallized Cd tribromide counterpart, MACdBr(3), was synthesized using a solvent-free ball-milling procedure for potential application in future solar cells. High angular resolution synchrotron x-ray diffraction revealed structural details, with UV-vis spectra showing a 4.6 eV band gap suitable for ultraviolet detectors.