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: 2*4*4

Basis set definition: tight

Numerical accuracy: force convergence 5e-3 eV/AA

Comment: See Table S2 of Wright et al. (https://doi.org/10.1021/acs.chemmater.1c04213). This is the lowest-energy structure among multiple possible atomic structure models for (PEA)2PbI4 investigated in this reference. This structure was constructed based on the experimental c(2*2)*2 (PEA)2PbI4 published by Du. et al. (doi: 10.1021/acs.inorgchem.7b01094.)

• Rayan C Duke University

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: 2*4*4

Basis set definition: tight

Numerical accuracy: force convergence 5e-3 eV/AA

Comment: See Table S2 of Wright et al. (https://doi.org/10.1021/acs.chemmater.1c04213). This structure was constructed based on the experimental (PEA)2PbI4 structure published by Febriansyah et al. (doi: 10.1021/acs.chemmater.8b04064.)

• Rayan C Duke University

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: 2*4*4

Basis set definition: tight

Numerical accuracy: force convergence 5e-3 eV/AA

Comment: See Table S2 of Wright et al. (https://doi.org/10.1021/acs.chemmater.1c04213). This structure was constructed based on the experimental T= 100 k (PEA)2PbI4 structure published by Straus et al. (doi: 10.1021/acs.jpclett.9b00247.)

• Rayan C Duke University

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: 2*4*4

Basis set definition: tight

Numerical accuracy: force convergence 5e-3 eV/AA

Comment: See Table S2 of Wright et al. (https://doi.org/10.1021/acs.chemmater.1c04213). This structure was constructed based on the experimental T= 300 k (PEA)2PbI4 structure published by Straus et al. (doi: 10.1021/acs.jpclett.9b00247.)

• Rayan C Duke University

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: See Table S4 of Ref. https://doi.org/10.1021/acs.chemmater.1c04213 . This is the lowest-energy computationally assessed structure of (PEA)2PbBr4 in that paper. This structure is constructed based on the experimental (PEA)2PbBr4 published by Shibuya et al. (doi: 10.1107/S160053680903712X)

• Rayan C Duke University

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

Numerical accuracy: force convergence 5e-3 eV/AA

Comment: See Table S4 of Ref. https://doi.org/10.1021/acs.chemmater.1c04213 . This structure is constructed based on the experimental T= RT (PEA)2PbBr4 published by Gong et al. (doi: 10.1038/s41563-018-0081-x.)

• Rayan C Duke University

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

Numerical accuracy: force convergence 5e-3 eV/AA

Comment: See Table S4 of Ref. https://doi.org/10.1021/acs.chemmater.1c04213 . The original structure is constructed based on the experimental T= 100K (PEA)2PbBr4 published by Gong et al. (doi: 10.1038/s41563-018-0081-x.)

• Rayan C Duke University

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

Numerical accuracy: force convergence 5e-3 eV/AA

Comment: See Table S4 of Ref. https://doi.org/10.1021/acs.chemmater.1c04213 . The original structure is constructed based on the experimental T= 100K (PEA)2PbBr4 published by Gong et al. (doi: 10.1038/s41563-018-0081-x.)

• Rayan C Duke University

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

Numerical accuracy: force convergence 5e-3 eV/AA

Comment: See Table S4 of Ref. https://doi.org/10.1021/acs.chemmater.1c04213 . This structure is constructed based on the experimental T= RT (PEA)2PbBr4 published by Gong et al. (doi: 10.1038/s41563-018-0081-x.)

• Rayan C Duke University

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

Numerical accuracy: force convergence 5e-3 eV/AA

Comment: See Table S4 of Ref. https://doi.org/10.1021/acs.chemmater.1c04213 . This structure is constructed based on the experimental T= RT (PEA)2PbBr4 published by Gong et al. (doi: 10.1038/s41563-018-0081-x.)

• Rayan C Duke University

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: 2*4*4

Basis set definition: tight

Numerical accuracy: force convergence 5e-3 eV/AA

Comment: This structure is constructed based on the experimental (PEA)2PbBr4 published by Shibuya et al. (doi: 10.1107/S160053680903712X). This structure is the same as Data ID 1890 - however, the a axis is chosen as the out of plane axis and the supercell is doubled (out of plane) compared to the experimental structure and compared to Data ID 1890.

• Rayan C Duke University

Code: FHI-aims

Level of theory: DFT

Exchange-correlation functional: PBE

K-point grid: 4*4*2

Level of relativity: atomic ZORA with SOC

Basis set definition: tight

Numerical accuracy: force convergence 5e-3 eV/AA

Comment: This is a variant of structure 1885, rotated to use the c axis instead of the a axis as the out of plane axis. This structure is constructed based on the experimental c(2*2)*2 (PEA)2PbI4 published by Du. et al. (doi: 10.1021/acs.inorgchem.7b01094.)

• Rayan C Duke University

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: This is a hypothetical, computationally generated structure that is intentionally NOT consistent with the experimental structure of (PEA)2PbI4. Rather, the organic molecule configuration of this structure is borrowed from (PEA)2PbBr4 structure (data ID 1890) but inorganic component is PbI4, then computationally fully optimized using DFT-PBE+TS.

• Rayan C Duke University

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: This is a hypothetical, computationally generated structure that is intentionally NOT consistent with the experimental structure of (PEA)2PbBr4. Rather, the organic molecule configuration of this structure is borrowed from (PEA)2PbI4 structure (data ID 1901) but inorganic component is PbBr4, then fully optimized.

• Rayan C Duke University

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: N/A

Method: Method: DFT-PBE plus Tkatchenko Scheffler dispersion, fully optimized

Comment: Structure published in reference table S12

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)

Starting materials: N/A

Comment: Structure published in reference table S13 (lowest energy structure)

Method: Manual entry, Method: DFT-PBE plus Tkatchenko Scheffler dispersion, fully optimized

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)

Starting materials: N/A

Comment: Structure published in reference table S14 (second lowest energy structure)

Method: Manual entry

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)

Starting materials: phenethylammonium iodide (C8H12IN), lead iodide (PbI2)

Product: thin film

Description: (PEA)I, amd PbI2 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.

Starting materials: phenethylammonium iodide (C8H12IN), lead iodide (PbI2)

Product: thin film

Description: (PEA)I, amd PbI2 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 photoluminescence

Description: PL spectroscopy measurements were taken using a HORIBA Jobin Yvon LabRam ARAMIS system. All films were excited using a 325 HeCd laser source with a 1% filter. Samples were kept in ambient air conditions.

Starting materials: phenethylammonium bromide (C8H12BrN), lead bromide (PbBr2)

Product: Thin film of (C12H25NH3)2PbBr4

Description: (PEA)Br 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.

Starting materials: phenethylammonium bromide (C8H12BrN), lead bromide (PbBr2)

Product: Thin film of (C12H25NH3)2PbBr4

Description: (PEA)Br 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: PL spectroscopy measurements were taken using a HORIBA Jobin Yvon LabRam ARAMIS system. All films were excited using a 325 HeCd laser source with a 1% filter. Samples were kept in ambient air conditions.

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.

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.

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.