Multicolor Heterostructures of Two-Dimensional Layered Halide Perovskites that Show Interlayer Energy Transfer

• Published in: Journal of the American Chemical Society 2018-11, Vol.140 (46), p.15675-15683
• Main Authors: Fu, Yongping, Zheng, Weihao, Wang, Xiaoxia, Hautzinger, Matthew P, Pan, Dongxu, Dang, Lianna, Wright, John C, Pan, Anlian, Jin, Song
• Format: Article
• Language: English
• Subjects: Chemistry
• ISSN: 0002-7863; 1520-5126
• DOI: 10.1021/jacs.8b07843

Fabrication of heterostructures using two-dimensional (2D) materials with different bandgaps creates opportunities for exploring new properties and device applications. Ruddlesden–Popper (RP) layered halide perovskites have recently emerged as a new class of solution-processable 2D materials that demonstrate exotic optoelectronic properties. However, heterostructures using 2D halide perovskites have not been achieved. Here, we report a simple solution growth method for making vertically stacked double heterostructures and complex multilayer heterostructures of 2D lead iodide perovskites [(PEA)2(MA) n–1Pb n I3n+1, PEA = C6H5(CH2)2NH3 +, MA = CH3NH3 +] via van der Waals epitaxy. These heterostructures present atomically sharp interfaces and display distinct photoluminescence that allow fingerprinting the RP phases. Time-resolved photoluminescence measurements reveal internal energy transfer from higher energy bandgap (lower n value) perovskite layers to lower energy bandgap (higher n value) perovskite layers on the time scale of hundreds of picoseconds due to natural type I band alignments. These results offer new strategies to fabricate perovskite–perovskite heterojunctions by taking advantage of surface-bound ligands as spatial barriers to prevent ion migration across the junctions. These heterostructures capable of multicolor emission with high spectral purity are promising for light-emitting applications.