Sequential Co‐Deposition of Perovskite Film: An Effective Way of Tailoring Bandgap in All Vacuum Processed Perovskite Solar Cells
This study introduces a simple and effective way to control the bandgap of perovskite film by constructing bilayer film composed of methylammonium lead iodide (MAPbI<sub>3</sub>) and formamidinium lead iodide (FAPbI<sub>3</sub>) layers. The bilayer film is fabricated through the sequential co-deposition of methylammonium iodide (MAI) and lead iodide (PbI<sub>2</sub>), followed by formamidinium iodide (FAI) and PbI<sub>2</sub>. Interestingly, the bandgap of the bilayer film can be tuned from 1.60 to 1.51 eV by adjusting the thickness of each layer. X-ray photoelectron spectroscopy (XPS) indicates that the highly diffusive methylammonium ions (MA<sup>+</sup>) enables the formation of stable α-phase with formamidinium ions (FA<sup>+</sup>) in the bilayer perovskite film even without further thermal annealing. Bilayer film-based perovskite solar cells (PSCs) are fabricated through an all-vacuum deposition process. The bilayer PSC exhibits higher power conversion efficiency (PCE) of 17.0% compared to the single-layer PSC based on MAPbI<sub>3</sub> or FAPbI<sub>3</sub>.
Authors
- Young Seon Yoon
- Shafidah Shafian
- Kyungkon Kim (ORCID: https://orcid.org/0000-0002-0115-8112)
- Jin Young Kim (ORCID: https://orcid.org/0000-0003-4822-3804)
- Sojeong Lee (ORCID: https://orcid.org/0000-0002-5131-3977)
Institutions
- Ewha Womans University (KR)
- Seoul National University (KR)
- National University of Malaysia (MY)
Publication Details
- Journal
- Small Methods
- Published
- 2025-04-14
- DOI
- https://doi.org/10.1002/smtd.202500104
- Citations
- 5
- Primary Topic
- Perovskite Materials and Applications
- Type
- article
- Field-Weighted Citation Impact
- 3.65
Funders
- National Research Foundation
- Ministry of Trade, Industry and Energy
- National Research Foundation of Korea
- Ministry of Science and ICT, South Korea
- Korea Institute of Energy Technology Evaluation and Planning