Layer-by-layer epitaxial growth of perovskite heterostructures with tunable band offsets

• 成果类型: Article
• 署名作者: Lu, Yang; Jung, Young-Kwang; Dubajic, Milos; Li, Xinjuan; Maqbool, Shabnum; Gu, Qichun; Bai, Xinyu; Boeije, Yorrick; Chua, Xian Wei; Mirabelli, Alessandro J.; Kang, Taeheon; Sonneveld, Lars; Zhang, Youcheng; Selby, Thomas A.; Mamak, Capucine; Tang, Kan; Yu, Zhongzheng; Liu, Tianjun; Anaya, Miguel; Barlow, Stephen; Marder, Seth R.; Ehrler, Bruno; Ducati, Caterina; Friend, Richard H.; Stranks, Samuel D.
• 署名单位: University of Cambridge; University of Cambridge; University of Cambridge; AMOLF; University of Colorado System; University of Colorado Boulder; University of Colorado System; University of Colorado Boulder; University of Colorado System; University of Colorado Boulder
• 刊物名称: SCIENCE
• ISSN/ISSBN: 0036-8075; 1095-9203
• DOI: 10.1126/science.adx5685
• 发表日期: 2025-11-13
• 页码: 716-721
• 关键词: halide perovskites; EFFICIENCY; physics; films

摘要

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 CsPbBr3 deposition on single crystals of PEA2PbBr4 (PEA: 2-phenylethylammonium). Angstrom-level thickness control and subangstrom smooth layers enable quantum-confined photoluminescence of CsPbBr3 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 CsPbBr3 to PEA2PbBr4 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.