The cubic (or near-cubic) black phase. This is the photoactive phase used in solar cells because its bandgap (~1.48 eV) is nearly ideal for capturing sunlight.
Finding a single, definitive CIF file for FAPbI$_3$ is more difficult than for simple salts like NaCl because of . fapbi3 cif file
CIF file is the bridge between a theoretical miracle and a tangible, high-efficiency solar panel on your roof. of the FAPbI CIF (like the cubic -phase or the hexagonal -phase) for a simulation? The cubic (or near-cubic) black phase
-phase, which features face-sharing octahedra and is unsuitable for solar applications due to its wide band gap (~ Key CIF Parameters for FAPbI3cap F cap A cap P b cap I sub 3 Standard CIF data for the cubic phase at approximately typically includes: Roughly Cell Volume: ~ FA+cap F cap A raised to the positive power Cation Orientation: The organic FA+cap F cap A raised to the positive power CIF file is the bridge between a theoretical
To proceed:
The crystallography of hybrid organic-inorganic perovskites (HOIPs) is complicated by the dynamic disorder of the organic A-site cation. In FAPbI$_3$, the FA$^+$ ion is larger than the MA$^+$ ion (ionic radius $\approx$ 2.53 Å vs 2.17 Å), exerting higher internal pressure on the PbI$_6$ octahedral framework. This results in a delicate thermodynamic balance between the cubic perovskite phase ($\alpha$-FAPbI$_3$) and the yellow, non-perovskite hexagonal phase ($\delta$-FAPbI$_3$).