Correlating Broadband Photoluminescence with Structural Dynamics in Layered Hybrid Halide Perovskites

• DOI: 10.1021/jacs.1c11217
• Publication Date: 2022-01-14T14:31:41Z
• Authors: Alexandra A. Koegel; Eve M. Mozur; Iain W. H. Oswald; Niina H. Jalarvo; Timothy R. Prisk; Madhusudan Tyagi; James R. Neilson
• Keywords: Colloid and Surface Chemistry; General Chemistry; 02 engineering and technology; 0210 nano-technology; Biochemistry; 530; Catalysis

The emission of white light from a single material is atypical and interest for solid-state lighting applications. Broadband has been observed in some layered perovskite derivatives, A2PbBr4 (A = R-NH3+), correlates with static structural distortions corresponding to out-of-plane tilting the lead bromide octahedra. While materials different organic cations can yield distinct tilts, underlying origin octahedral remains poorly understood. Using high energy resolution (e.g., quasi-elastic) neutron scattering, this contribution details rotational dynamics where A n-butylammonium (nBA), 1,8-diaminooctammonium (ODA), 4-aminobutyric acid (GABA). cation differentiate (nBA)2PbBr4 (ODA)PbBr4 or (GABA)2PbBr4 that larger spatial extent nBA yields effective radius. volume closer ideal A-site geometry, preventing tilt broadband luminescence. In all three compounds, we observe hydrogen attributed rotation ammonium headgroup at time scale faster than photoluminescence studied by time-correlated photon counting spectroscopy. This supports previous assignment as resulting ensemble, such emissive excited state experiences many local structures decay. findings presented here highlight role its hybrid organic-inorganic perovskites emission.