Abstract
Solvent is vital in determining the colloidal chemistry of perovskite ink. A depth understanding on the colloidal chemistry is essential to fine-regulate the crystallization of perovskite film. A low-polar solvent, 2-methoxyethanol (2-Me), shows growing potential than the traditional high-polar solvents in scaling-up perovskite solar cells, owing to the fast evaporation rate and the ability to form perovskite films without anti-solvent. However, as a relatively new solvent, the colloidal chemistry has not been fully understood. Here, the colloidal chemistry of fresh and aged perovskite ink using 2-Me as the solvent is investigated. The as-composed perovskite ink is characteristic of weakly bonded I- ions and the existence of cluster complexes. In the fresh perovskite ink, the weakly bonded I- ions enhance the dissolution of methylammonium (MA+), and also induce the formation of I3- ions in the diluted or aged solution. Both iodoplumbate species and cluster complexes are dispersed by MA+ ions in the solution, however, the former transforms to clusters after aging. These changes results in increased crystal size and non-uniform coverage in the perovskite film. These findings provide valuable insights into the optimization of perovskite ink using 2-Me as the solvent.
Original language | English |
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Article number | 132406 |
Journal | Colloids and Surfaces A: Physicochemical and Engineering Aspects |
Volume | 677 |
DOIs | |
Publication status | Published - 20 Nov 2023 |
Keywords
- 2-Methoxyethanol
- Aging
- Cluster
- Colloidal chemistry
- Iodoplumbate