Kim, Kitae Park, Chanhui Cha, Eunseo Kang, Donghee Park, Jeehong Cho, Sangwan Yi, Yeonjin Park, Soohyung 2024-01-19T09:34:34Z 2024-01-19T09:34:34Z 2023-04-20 2023-04 2515-7655 https://pubs.kist.re.kr/handle/201004/113830 Two-dimensional Ruddlesden-Popper (2DRP) perovskites are promising owing to their excellent environmental stability and competitive efficiency. During the fabrication process, 2DRP perovskites were often unintentionally exposed to light in the laboratory. However, the influence of light illumination on the surface structure of 2DRP during fabrication is unclear. Herein, the photodegradation of 2DRP perovskite (phenethylammonium lead iodide, PEA(2)PbI(4)) is comprehensively investigated using x-ray photoelectron spectroscopy, scanning electron microscopy, atomic force microscopy, and photoluminescence spectroscopy. We observed that only high-energy light, including that from a blue laser, air mass 1.5G, and notably, the daily used fluorescent lamp (FL) in the laboratory, significantly degraded PEA(2)PbI(4). However, the red laser and ultraviolet-filtered FL, which had low energies, did not cause photodegradation. From this systematic study, we can explain the discrepancies in the surface morphologies previously studied. For instance, randomly oriented nanorod or rough surface of PEA(2)PbI(4) mostly stems from photodegradation. We observed that photodegradation occurred more strongly when the films were illuminated during annealing than when they were illuminated after all fabrication processes were completed. We suggest that this difference stems from the completeness of the structure and the photodegraded PbI2 passivation effect. Our study provides two key guidelines for the fabrication of PEA(2)PbI(4) films. The daily-use FL in the laboratory must be avoided for high-quality samples, and dark conditions are highly recommended, at least during the annealing process. English IOP Publishing Impact of light illumination on the surface structure of two-dimensional Ruddlesden-Popper perovskite in the fabrication process Article 10.1088/2515-7655/acc2e6 1 JPhys Energy, v.5, no.2 JPhys Energy 5 2 Y scie scopus 000958077200001 2-s2.0-85151572055 Energy & Fuels Materials Science, Multidisciplinary Energy & Fuels Materials Science Article METALLIC LEAD photodegradation surface structure x-ray photoelectron spectroscopy scanning electron microscope 2D Ruddlesden-Popper perovskite atomic force microscope photoluminescence