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Updated: Mar 13, 2026
Influence of Hybrid Perovskite Fabrication Methods on Film Formation, Electronic Structure, and Solar Cell Performance
Published on: February 27, 2017
Ultrafast ion migration in hybrid perovskite polycrystalline thin films under light and suppression in single
Jie Xing1, Qi Wang2, Qingfeng Dong2
1Department of Mechanical and Materials Engineering, University of Nebraska-Lincoln, Lincoln, 68588, NE, USA. jhuang2@unl.edu and School of Science, China University of Geosciences, Beijing, 100083, P. R. China.
Abstract:
Understanding the influence of light on ion migration in organic-inorganic halide perovskite (OIHP) materials is important to understand the photostability of perovskite solar cells. We reveal that light could greatly reduce the ion migration energy barrier in both polycrystalline and single crystalline OIHP. The activation energies derived from conductivity measurement under 0.25 Sun decrease to less than one half of the values in the dark. A typical ion drift velocity in CH3NH3PbI3 polycrystalline films is 1.2 μm s-1 under 1 Sun, compared with 0.016 μm s-1 under 0.02 Sun. Ion migration across the photoactive layers in most OIHP devices thus takes only subseconds under 1 Sun illumination, which is much shorter than what it was thought to take. Most important of all, ion migration through a single crystal surface is still too slow to be observed even after illumination for two days due to the large ion diffusion activation energy, >0.38 eV.
