Interlayer Triplet Energy Transfer in Dion–Jacobson Two-Dimensional Lead Halide Perovskites Containing Naphthalene Diammonium Cations

• Published in: The journal of physical chemistry letters Vol. 12; no. 20; pp. 4793 - 4798
• Main Authors: Lin, YunHui L, Johnson, Justin C
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 27-05-2021
• Subjects: 2D perovskite; energy transfer; excimer; INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; low dimensional perovskite; perovskite; phosphorescence; photoluminescence; Physical Insights into Light Interacting with Matter; solar-photochemistry; triplet energy transfer; triplet sensitization
• ISSN: 1948-7185; 1948-7185
• DOI: 10.1021/acs.jpclett.1c01232

Recently, hybrid perovskites have gained attention as sensitizers for molecular triplet generation. Layered, two-dimensional (2D) perovskites are especially well-suited for this purpose because the triplet donor (inorganic framework) and triplet acceptor (organic layer) are self-assembled into adjacent sheets, so that with the appropriate energetics, triplets can be driven across the interface. Here we examine interlayer energy transfer in a series of mixed-halide Dion–Jacobson 2D perovskites containing divalent naphthalene cations. We find that the sensitized phosphorescence in these compounds is dominated by naphthalene triplet excimer emission, but when the inorganic exciton is tuned near resonance with the naphthalene triplet, naphthalene monomer phosphorescence competes with triplet excimer formation. The interlayer energy-transfer process is further revealed by ultrafast transient absorption spectroscopy through kinetic variations in triplet excimer formation times. Ultimately, gaining control over interlayer interactions in 2D perovskites through cation design will help uncover new functions and applications for these materials.