Structure and Surface Passivation of Ultrathin Cesium Lead Halide Nanoplatelets Revealed by Multilayer Diffraction

Summary, in English

The research on two-dimensional colloidal semiconductors has received a boost from the emergence of ultrathin lead halide perovskite nanoplatelets. While the optical properties of these materials have been widely investigated, their accurate structural and compositional characterization is still challenging. Here, we exploited the natural tendency of the platelets to stack into highly ordered films, which can be treated as single crystals made of alternating layers of organic ligands and inorganic nanoplatelets, to investigate their structure by multilayer diffraction. Using X-ray diffraction alone, this method allowed us to reveal the structure of ∼12 Å thick Cs-Pb-Br perovskite and ∼25 Å thick Cs-Pb-I-Cl Ruddlesden-Popper nanoplatelets by precisely measuring their thickness, stoichiometry, surface passivation type and coverage, as well as deviations from the crystal structures of the corresponding bulk materials. It is noteworthy that a single, readily available experimental technique, coupled with proper modeling, provides access to such detailed structural and compositional information.

• Author: Stefano Toso; Dmitry Baranov; Cinzia Giannini; Liberato Manna
• Publishing year: 2021-12-28
• Language: English
• Pages: 20341-20352
• Publication/Series: ACS Nano
• Volume: 15
• Issue: 12
• Links: http://dx.doi.org/10.1021/acsnano.1c08636
• Document type: Journal article
• Publisher: The American Chemical Society (ACS)
• Keywords: lead halide perovskite; multilayer diffraction; nanoplatelet; Ruddlesden-Popper; structure; surface; X-ray
• Status: Published
• ISBN/ISSN/Other: ISSN: 1936-0851