Crystal structure features of CH₃NH₃PbI_3−xBr_x hybrid perovskites prepared by ball milling: a route to more stable materials

Abstract

Hybrid organic–inorganic perovskites, MAPbX3 (MA: CH3–NH3+; X = halogen), prepared by ball milling are, by far, much more stable towards ambient conditions (air, humidity) than the conventional materials prepared from solution chemistry.

Structural evolution, optical gap and thermoelectric properties of CH3NH3SnBr3 hybrid perovskite, prepared by mechanochemistry

“…The paradigmatic methyl-ammonium lead iodide CH 3 NH 3 PbI 3 has thus emerged as light harvester for hetero-junction solar cells [7][8][9] . Other direct bandgap semiconductors of the MAPbX 3 (MA= CH 3 NH 3 , X= I, Br, I) family exhibit properties such as outstanding light absorption, excellent ambipolar charge mobility, low exciton binding energy and tolerance to defects [10][11][12][13][14][15][16][17][18] . However, all of them contain poisonous lead, involving toxicity issues with potential public health problems 19 .…”

Recent Advances and Perspectives on Powder‐Based Halide Perovskite Film Processing

“…Compared to solvent-based powders, they attributed the increased stability to a lower inclination angle of the PbI 6 octahedrons, presumably caused by a small MA deficiency, leading to a higher Goldschmidt's tolerance factor. [45] Another important aspect about mechanochemically synthesized perovskite powders is their ability to incorporate advances made for traditional synthesis approaches, such as solutionbased synthesis approaches. In comparison to single crystals, polycrystalline perovskites exhibit a higher trap density, which increases nonradiative recombination and facilitates ion migration.…”

“…Compared to solvent‐based powders, they attributed the increased stability to a lower inclination angle of the PbI 6 octahedrons, presumably caused by a small MA deficiency, leading to a higher Goldschmidt's tolerance factor. [ 45 ]…”

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

“…In particular, methyl-ammonium lead iodide CH 3 NH 3 PbI 3 (CH 3 NH 3 + : MA) is the prototype of light harvester in hetero-junction solar cells [5][6][7]. Hybrid perovskites MAPbX 3 (X = I, Br and Cl) also exhibit properties such as ambipolar charge mobility, low exciton binding energy and tolerance to structural defects [8][9][10][11][12][13][14]. Other divalent elements instead of Pb 2+ have been evaluated; experimental [15] and theoretical [16,17] studies have been carried out for other divalent cations, such as those of Group 12 (Zn, Cd and Hg) that also are closed-shell divalent cations.…”