Layer-by-layer epitaxial growth of perovskite heterostructures with tunable band offsets
Halide perovskites exhibit superior optoelectronic properties but lack precise thickness and band offset control in heterojunctions, which is critical for modular multilayer architectures such as multiple quantum wells. We demonstrate vapor-phase, layer-by-layer heteroepitaxial growth exemplified by CsPbBr<sub>3</sub> deposition on single crystals of PEA<sub>2</sub>PbBr<sub>4</sub> (PEA: 2-phenylethylammonium). Angstrom-level thickness control and subangstrom smooth layers enable quantum-confined photoluminescence of CsPbBr<sub>3</sub> from monolayer, bilayer, and through to bulk. The interfacial structure controls the electronic structure from a Cs‒PEA-terminated interface (type II heterojunction) to a PEA‒PEA-terminated interface (type I heterojunction), with a layer-tunable band offset shift exceeding 0.5 electron volts. Electron transfer from CsPbBr<sub>3</sub> to PEA<sub>2</sub>PbBr<sub>4</sub> for a type II Cs‒PEA heterojunction results in delayed electron-hole recombination beyond 10 microseconds. Precise quantum confinement control and large band offset tunability unlock perovskite heterojunctions as platforms for scalable, superlattice-based optoelectronic applications.
Authors
- Caterina Ducati (ORCID: https://orcid.org/0000-0003-3366-6442)
- Xian Wei Chua (ORCID: https://orcid.org/0000-0003-3015-6834)
- Yorrick Boeije (ORCID: https://orcid.org/0000-0002-4346-3123)
- Zhongzheng Yu (ORCID: https://orcid.org/0000-0003-0941-3357)
- Miguel Anaya (ORCID: https://orcid.org/0000-0002-0384-5338)
- Bruno Ehrler (ORCID: https://orcid.org/0000-0002-5307-3241)
- Seth R. Marder (ORCID: https://orcid.org/0000-0001-6921-2536)
- Alessandro J. Mirabelli (ORCID: https://orcid.org/0000-0001-7101-4926)
- Xinjuan Li (ORCID: https://orcid.org/0000-0003-3086-9287)
- Richard Henry Friend (ORCID: https://orcid.org/0000-0001-6565-6308)
- Kan Tang (ORCID: https://orcid.org/0000-0003-0012-0224)
- Xinyu Bai (ORCID: https://orcid.org/0000-0002-0910-758X)
- Miloš Dubajić (ORCID: https://orcid.org/0000-0001-9494-8967)
- Stephen Barlow (ORCID: https://orcid.org/0000-0001-9059-9974)
- Taeheon Kang (ORCID: https://orcid.org/0009-0009-8089-2339)
- Young‐Kwang Jung (ORCID: https://orcid.org/0000-0003-3848-8163)
- Samuel D. Stranks (ORCID: https://orcid.org/0000-0002-8303-7292)
- Tianjun Liu (ORCID: https://orcid.org/0000-0002-3630-0414)
- Thomas A. Selby (ORCID: https://orcid.org/0009-0003-8655-5559)
- Shabnum Maqbool (ORCID: https://orcid.org/0000-0002-2708-1803)
- Lars Sonneveld (ORCID: https://orcid.org/0009-0005-2669-9539)
- Youcheng Zhang (ORCID: https://orcid.org/0000-0003-4233-9769)
- Qichun Gu (ORCID: https://orcid.org/0009-0004-1399-7601)
- Yang Lu (ORCID: https://orcid.org/0000-0002-2793-2065)
- Capucine Mamak (ORCID: https://orcid.org/0009-0000-6168-4862)
Institutions
- University of Colorado Boulder (US)
- University of Cambridge (GB)
- Sustainable Energy Systems (United Kingdom) (GB)
Publication Details
- Journal
- Science
- Published
- 2025-11-13
- DOI
- https://doi.org/10.1126/science.adx5685
- Citations
- 5
- Primary Topic
- Perovskite Materials and Applications
- Type
- article
- Field-Weighted Citation Impact
- 3.65