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Structural and Chemical Changes to CH 3 NH 3 PbI 3 Induced by Electron and Gallium Ion Beams
Author(s) -
Rothmann Mathias Uller,
Li Wei,
Zhu Ye,
Liu Amelia,
Ku Zhiliang,
Bach Udo,
Etheridge Joanne,
Cheng YiBing
Publication year - 2018
Publication title -
advanced materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.707
H-Index - 527
eISSN - 1521-4095
pISSN - 0935-9648
DOI - 10.1002/adma.201800629
Subject(s) - materials science , irradiation , electron beam processing , electron diffraction , ion , tetragonal crystal system , diffraction , electron , gallium , radiation damage , perovskite (structure) , analytical chemistry (journal) , crystallography , crystal structure , optics , chemistry , organic chemistry , physics , quantum mechanics , nuclear physics , metallurgy
Organic–inorganic hybrid perovskites, such as CH 3 NH 3 PbI 3, have shown highly promising photovoltaic performance. Electron microscopy (EM) is a powerful tool for studying the crystallography, morphology, interfaces, lattice defects, composition, and charge carrier collection and recombination properties at the nanoscale. Here, the sensitivity of CH 3 NH 3 PbI 3 to electron beam irradiation is examined. CH 3 NH 3 PbI 3 undergoes continuous structural and compositional changes with increasing electron dose, with the total dose, rather than dose rate, being the key operative parameter. Importantly, the first structural change is subtle and easily missed and occurs after an electron dose significantly smaller than that typically applied in conventional EM techniques. The electron dose conditions under which these structural changes occur are identified. With appropriate dose‐minimization techniques, electron diffraction patterns can be obtained from pristine material consistent with the tetragonal CH 3 NH 3 PbI 3 phases determined by X‐ray diffraction. Radiation damage incurred at liquid nitrogen temperatures and using Ga + irradiation in a focused ion beam instrument are also examined. Finally, some simple guidelines for how to minimize electron‐beam‐induced artifacts when using EM to study hybrid perovskite materials are provided.