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Metal Coordination Sphere Deformation Induced Highly Stokes-Shifted,Ultra Broadband Emission in 2D Hybrid Lead-Bromide Perovskites and Investigation of Its Origin |
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| Authors: | Benny Febriansyah Dr Tetiana Borzda Dr Daniele Cortecchia Dr Stefanie Neutzner Dr Giulia Folpini Dr Teck Ming Koh Dr Yongxin Li Prof Nripan Mathews Prof Annamaria Petrozza Prof Jason England |
| Institution: | 1. Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore, 637371 Singapore
Energy Research Institute at Nanyang Technological University (ERI@N), Research Techno Plaza, X-Frontier Block Level 5, 50 Nanyang Drive, Singapore, 637553 Singapore Interdiscipinary Graduate School (IGS), 50 Nanyang Avenue, Singapore, 639798 Singapore These authors contributed equally to this work.;2. Center for Nano Science and Technology@Polimi, Istituto Italiano di Tecnologia, 8 via Giovanni Pascoli 70/3, 20133 Milan, Italy These authors contributed equally to this work.;3. Center for Nano Science and Technology@Polimi, Istituto Italiano di Tecnologia, 8 via Giovanni Pascoli 70/3, 20133 Milan, Italy;4. Energy Research Institute at Nanyang Technological University (ERI@N), Research Techno Plaza, X-Frontier Block Level 5, 50 Nanyang Drive, Singapore, 637553 Singapore;5. Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore, 637371 Singapore;6. Energy Research Institute at Nanyang Technological University (ERI@N), Research Techno Plaza, X-Frontier Block Level 5, 50 Nanyang Drive, Singapore, 637553 Singapore School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798 Singapore |
| Abstract: | Published studies of layered (2D) (100)-oriented hybrid lead-bromide perovskites evidence a correlation between increased inter-octahedral (Pb-Br-Pb) distortions and the appearance of broadband white light emission. However, the impact of distortions within their constituent PbBr6]4? octahedra has yet to be assessed. Herein, we report two new (100)-oriented 2D Pb-Br perovskites, whose structures display unusually high intra-octahedral distortions, whilst retaining minimal inter-octahedral distortions. Using a combination of temperature-dependent, power-dependent and time-resolved photoluminescence spectroscopic measurements, we show that increased intra-octahedral distortion induces exciton localization processes and leads to formation of multiple photoinduced emissive colour centres. Ultimately, this leads to highly Stokes-shifted, ultrabroad white light emission at room temperature. |
| Keywords: | crystal engineering intra-octahedral distortion lead-bromide perovskites photophysics white-light emission |