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Allen et al. J Mater Inf 2024;4:35 https://dx.doi.org/10.20517/jmi.2024.72 Page 3 of 15

quickly return average crystal grain sizes that agree with the results for the standard method.

Finally, we fabricate p-i-n PSCs using the optimized PC MAPbI condition with a NiO hole transport layer
3
x
(HTL) at the bottom. Unexpectedly, our optimized PC PSCs exhibit significantly lower PCEs than TA
devices despite their similar UV-vis absorbance. Based on the film temperature simulation using Simpulse®,
we hypothesize that this is caused by an elevated MAPbI film temperature during PC, resulting in
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previously known interfacial reaction between NiO HTL and the MAPbI active layer [22,23] . We find that the
x
3
use of a buffer layer on top of the NiO alleviates this reaction, significantly improving the PCE for PSCs
x
made with PC MAPbI .
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MATERIALS AND METHODS
Materials
Patterned and unpatterned indium tin oxide (ITO) substrates (10 ohm/sq) were purchased from Kintec.
Lead iodide (PbI ) was purchased from TCI America and methylammonium iodide (MAI) was purchased
2
from GreatCell Solar. All other chemicals were purchased from Sigma-Aldrich or Fisher. Chemicals were
used as received unless otherwise specified.

Perovskite film preparation for training dataset
Samples for the training dataset were prepared on unpatterned ITO substrates. The MAPbI precursor was
3
prepared using established procedures [24,25] . Briefly, equal molar PbI and MAI were dissolved in
2
2-methoxyethanol (2-MOE) to make a 0.8 M solution with 40 mole % of N-methyl-2-pyrrolidone (NMP).
The MAPbI precursor was deposited onto spinning ITO substrates at 5,000 rpm for 15 s in a N -filled
2
3
glovebox. For thermal annealed (TA) samples, the MAPbI precursor films were immediately annealed at
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100 °C for 10 min inside the glovebox, while the PC samples were transferred to a Pulse Forge Invent PC
tool and pulsed in ambient air with conditions given in Supplementary Table 1.
PSC fabrication
We used patterned ITO substrates to make p-i-n PSCs. The substrates were cleaned sequentially with soapy
water, deionized (DI) water, acetone, and isopropanol, followed by a 20-min UV-ozone treatment. The
NiO precursor was prepared according to the following instructions. First, 0.1 M nickel nitrate hexahydrate
x
and acetylacetone in 2-MOE were stirred overnight, and the solution was filtered through a 0.2 µm
polytetrafluoroethylene (PTFE) filter immediately before usage. 60 µL of NiO precursor was spin-coated at
3,000 rpm for 30 s onto each sample followed by drying at 60 °C for 3 min. The temperature was increased
to 150 °C and held for 5 min before increasing to 250 °C for calcination for a further 30 min. The hot plate
was then turned off and the samples were allowed to cool for 20 min.

The samples were then either transferred to a glovebox for MAPbI precursor deposition or had a PbI or a
2
3
[2-(3,6-Dimethoxy-9H-carbazol-9-yl)ethyl]phosphonic Acid (MeO-2PACz) buffer layer added. A PbI
2
buffer layer was applied by spin coating 0.1 M PbI in dimethylformamide (DMF) at 3,000 rpm for 50 s in
2
an N -purged glovebox before annealing at 100 °C for 15 min . The samples were then taken out of the
[26]
2
glovebox and rinsed with an additional 1 mL of DMF to remove unbound residual PbI before being dried
2
and returned to the glovebox. A MeO-2PACz buffer layer was made by spin coating a 0.5 mg/mL solution
of MeO-2PACz in ethanol at 3,000 rpm for 30 s in ambient air before transferring to an N glovebox for TA
2
[27]
at 100 °C for 10 min .
All samples were then spin-coated with the MAPbI precursor as described in the previous sub-section.
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Subsequently, the electron transport layer (ETL) was deposited by spin coating 20 mg/mL