Exploring nanoscale structure in perovskite precursor solutions using neutron and light scattering

Journal article

Tailoring the solution chemistry of metal halide perovskites requires a detailed understanding of precursor aggregation and coordination. In this work, we use various scattering techniques, including dynamic light scattering (DLS), small angle neutron scattering (SANS), and spin-echo SANS (SESANS) to probe the nanostructures from 1 nm to 10 μm within two different lead-halide perovskite solution inks (MAPbI3and a triple-cation mixed-halide perovskite). We find that DLS can misrepresent the size distribution of the colloidal dispersion and use SANS/SESANS to confirm that these perovskite solutions are mostly comprised of 1-2 nm-sized particles. We further conclude that if there are larger colloids present, their concentration must be <0.005% of the total dispersion volume. With SANS, we apply a simple fitting model for two component microemulsions (Teubner-Strey), demonstrating this as a potential method to investigate the structure, chemical composition, and colloidal stability of perovskite solutions, and we here show that MAPbI3solutions age more drastically than triple cation solutions.

Authors: O'Kane, ME; Smith, JA; Kilbride, RC; Spooner, ELK; Duif, CP

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: American Chemical Society
• Journal: Chemistry of Materials
• Volume: 34
• Issue: 16
• Pages: 7232-7241
• Publication date: 2022-08-03
• Acceptance date: 2022-07-24
• DOI: 10.1021/acs.chemmater.2c00905
• EISSN: 1520-5002
• ISSN: 0897-4756
• Language: English
• Keywords: FFR