Revealing the relationship between perovskite material structure and photostability!

• Halide perovskites are excellent candidates for solar cells, LEDs, and detector devices, in part because their composition can be tuned to achieve desired optoelectronic properties. Empirical efficiency optimization has led the field toward compositions rich in FA (formamide ) at the A site and I at the X site, while also containing small amounts of MA (methylammonium ) or Cs A site cations and Br X site anions.

  
  

  However, it is currently unclear how and why the specific composition of alloyed halide perovskites is related to the photostability of the material. Here, Miguel Anaya and Samuel D. Stranks of the University of Cambridge combined synchrotron radiation oblique incidence wide-angle X-ray scattering, photoluminescence, high-resolution scanning electron diffraction measurements and theoretical simulations to reveal the material structure and photostability the relationship between.

  
  

  Specifically, the authors found that increased octahedral tilt leads to improved photostability, associated with a reduced hexagonal polytype impurity density that impacts performance. The results reveal structural features that underpin photostability and can therefore be used to modify halide perovskites in a targeted manner, improving the commercial prospects of technologies based on these materials.

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• AN Iqbal, KWP Orr, S. Nagane, JF Orri, TAS Doherty, Y.-K. Jung, Y.-H. Chiang, TA Selby, Y. Lu, AJ Mirabelli, A. Baldwin, ZY Ooi, Q. Gu , M. Anaya, SD Stranks, Composition dictates octahedral tilt and photostability in halide perovskites. Adv. Mater. 2024, 2307508.

  
  

  https://doi.org/10.1002/adma.202307508