Crystal system: triclinic
| a: | 12.19780429 Å |
| b: | 12.07413733 Å |
| c: | 34.6429016 Å |
| α: | 100.0464887° |
| β: | 106.3953437° |
| γ: | 90.00531275° |
Code: FHI-aims
Level of theory: DFT
Exchange-correlation functional: PBE (with TS scheme to account for the Van der Waals effect)
K-point grid: 4*4*2
Basis set definition: tight
Numerical accuracy: force convergence 5e-3 eV/AA
Comment: The organic molecule configuration of this structure is borrowed from (PEA)2PbBr4 structure (data ID 1900). Structure published in Ref Table S11
Starting materials: phenethylammonium iodide (C8H12IN), phenethylammonium bromide (C8H12BrN), lead iodide (PbI2), lead bromide (PbBr2)
Product: thin film
Description: (PEA)I, (PEA)Br, PbI2, and PbBr2 made up the target solution in 1:1 DMSO/MEG by volume. They were mechanically mixed until visibly dissolved in solvent, taking about 5 min. In a growth chamber, the solution is cooled to -196°C under vacuum. When frozen, the top layer is removed using an Er:YAG laser (2.94 μm). The laser rasters across the surface to sublimate the MEG, causing the precursor material to be ejected onto the substrate (2 cm × 2 cm of SiO2 glass) spinning 7 cm above. The substrate temperature is approximately 10 °C while in the growth chamber. Deposit time was 4 h. Samples remained in a load lock under turbo vacuum (2 × 10–5 Torr) for an hour afterwards. The annealed films were additionally annealed for 10 min on a hot plate in an N2 environment at 110°.
Method: UV−vis Absorption
Description: UV−vis absorption spectra were acquired using a Shimadzu UV-3600 spectrophotometer. Samples of films on glass substrates were measured. Samples were kept in ambient air conditions.