Controlling Preferred Grain Orientation in Vapor-Deposited Metal-Halide Perovskite Thin Films

Journal Article · Mon Jun 02 00:00:00 EDT 2025 · The Journal of Physical Chemistry C

DOI:https://doi.org/10.1021/acs.jpcc.5c00165· OSTI ID:2997614

Pettit, Emma C. ^[1]; Hsu, Wan-Ju ^[1]; Garcia-Barriocanal, Javier ^[1]; Srinivasan, Shreyas ^[2]; Kadosh, Tamar ^[2]; Bulović, Vladimir ^[2]; Holmes, Russell J. ^[1]

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1. University of Minnesota, Minneapolis, MN (United States)
2. Massachusetts Institute of Technology, Cambridge, MA (United States)

Metal-halide perovskites are promising semiconductor materials for light-absorber layers in solar cells due to their optimized band gap, defect tolerance, and relative ease of synthesis. In this work, we demonstrate the viability of vapor transport deposition (VTD), a solvent-free processing method, to realize polycrystalline films of both lead iodide (PbI₂) and methylammonium lead iodide (MAPbI₃) perovskites showing preferential crystallographic orientation. Notable is the difference in perovskite film texturing observed for sequentially and co-deposited VTD films of MAPbI₃, as well as the lack of strong preferential orientation in solution-processed MAPbI₃ films. While sequential deposition of the perovskite precursors PbI₂ and methylammonium iodide (MAI) leads to a MAPbI₃ film with a limited preferential grain orientation, co-deposited MAPbI₃ films mirror the orientation of excess PbI₂ present in the film. The latter is confirmed by the similar dependence of preferential orientation for PbI₂ and co-deposited MAPbI₃ on underlayer roughness, as well as the emergence of preferential orientation in MAPbI₃ only when excess PbI₂ is present. Both MAPbI₃ and PbI₂ films show a strong preferred lattice orientation on smooth substrates, while on rougher substrates, this orientation is disrupted. Furthermore, these results are interpreted as excess PbI₂ frustrating the diffusion of MAI in the film, which would otherwise disrupt the preferred orientation, pointing to a notable difference in lattice orientation arising from processing technique and conditions.

• Research Organization: University of Minnesota, Minneapolis, MN (United States)
• Sponsoring Organization: USDOE Office of Energy Efficiency and Renewable Energy (EERE), Renewable Power Office. Solar Energy Technologies Office
• Grant/Contract Number: EE0009514
• OSTI ID: 2997614
• Journal Information: The Journal of Physical Chemistry C, Journal Name: The Journal of Physical Chemistry C Journal Issue: 23 Vol. 129; ISSN 1932-7455; ISSN 1932-7447
• Publisher: American Chemical Society (ACS)
• Country of Publication: United States
• Language: English

Related Subjects

Deposition
Diffraction
Lattices
Perovskites
Thin films