title: Transcending the slow bimolecular recombination in lead-halide perovskites for electroluminescence.
abstract: The slow bimolecular recombination that drives three-dimensional lead-halide perovskites' outstanding photovoltaic performance is conversely a fundamental limitation for electroluminescence. Under electroluminescence working conditions with typical charge densities lower than 1015cm-3, defect-states trapping in three-dimensional perovskites competes effectively with the bimolecular radiative recombination. Herein, we overcome this limitation using van-der-Waals-coupled Ruddlesden-Popper perovskite multi-quantum-wells. Injected charge carriers are rapidly localized from adjacent thin few layer (n≤4) multi-quantum-wells to the thick (n≥5) multi-quantum-wells with extremely high efficiency (over 85%) through quantum coupling. Light emission originates from excitonic recombination in the thick multi-quantum-wells at much higher decay rate and efficiency than bimolecular recombination in three-dimensional perovskites. These multi-quantum-wells retain the simple solution processability and high charge carrier mobility of two-dimensional lead-halide perovskites. Importantly, these Ruddlesden-Popper perovskites offer new functionalities unavailable in single phase constituents, permitting the transcendence of the slow bimolecular recombination bottleneck in lead-halide perovskites for efficient electroluminescence.
authors.affiliation: Institute of Applied Physics and Materials Engineering, University of Macau, Macao SAR 999078, China.
authors.forename: Guichuan
authors.initials: G
authors.lastname: Xing
authors.affiliation: Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore.
authors.forename: Bo
authors.identifier: 0000-0002-7177-9029
authors.initials: B
authors.lastname: Wu
authors.affiliation: Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore.
authors.forename: Xiangyang
authors.initials: X
authors.lastname: Wu
authors.affiliation: Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore.
authors.forename: Mingjie
authors.initials: M
authors.lastname: Li
authors.affiliation: Key Laboratory of Flexible Electronics (KLOFE) &Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University (Nanjing Tech), 30 South Puzhu Road, Nanjing 211816, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Du
authors.affiliation: Key Laboratory of Flexible Electronics (KLOFE) &Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University (Nanjing Tech), 30 South Puzhu Road, Nanjing 211816, China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Wei
authors.affiliation: Key Laboratory of Flexible Electronics (KLOFE) &Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University (Nanjing Tech), 30 South Puzhu Road, Nanjing 211816, China.
authors.forename: Jia
authors.initials: J
authors.lastname: Guo
authors.affiliation: Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore.
authors.forename: Edwin K L
authors.initials: EK
authors.lastname: Yeow
authors.affiliation: Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore.
authors.forename: Tze Chien
authors.identifier: 0000-0003-4049-2719
authors.initials: TC
authors.lastname: Sum
authors.affiliation: Key Laboratory of Flexible Electronics (KLOFE) &Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University (Nanjing Tech), 30 South Puzhu Road, Nanjing 211816, China.|Key Laboratory for Organic Electronics and Information Displays &Institute of Advanced Materials (IAM), SICAM, Nanjing University of Posts &Telecommunications, 9 Wenyuan Road, Nanjing 210023, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Huang