ISIS Neutron and Muon Source Data Journal

Origin of ultra-low thermal conductivity in Ruddlesden Popper 2D Perovskite Cs2PbI2Cl2: An Inelastic Neutron Scattering Study

Abstract: Crystalline solid with low thermal conductivity is crucial for high-performance thermoelectrics. Recently, we have demonstrated an intrinsically ultralow lattice thermal conductivity (?L) in 2D Ruddlesden?Popper (RP) perovskites Cs2PbI2Cl2. We have observed intrinsically ultralow ?L of ?0.37?0.28 W/mK in the 295?523 K temperature range when measured along the crystallographic c-axis. First-principles density functional theory analysis of the phonon spectrum exhibits low energy optical mode at ?12 cm?1 (1.5 meV) that originates from dynamic octahedral rotation around Pb caused by anharmonic vibration of Cl atoms induced by a 3s2 lone pair. Inelastic Neutron Scattering (INS) data as a function of temperature will enable us to extract these low energy optical modes, their phonon lifetimes, etc. and help us to investigate the fundamental cause for the intrinsically ultralow ?L in Cs2PbI2Cl2.

Principal Investigator: Dr Kanishka Biswas
Local Contact: Dr David Voneshen
Experimenter: Mr Moinak Dutta
Experimenter: Mr Paribesh Acharyya

DOI: 10.5286/ISIS.E.RB2000188

ISIS Experiment Number: RB2000188

Publisher: STFC ISIS Neutron and Muon Source

Data format: RAW/Nexus
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Data Citation

The recommended format for citing this dataset in a research publication is as:
[author], [date], [title], [publisher], [doi]

For Example:
Dr Kanishka Biswas et al; (2021): Origin of ultra-low thermal conductivity in Ruddlesden Popper 2D Perovskite Cs2PbI2Cl2: An Inelastic Neutron Scattering Study, STFC ISIS Neutron and Muon Source, https://doi.org/10.5286/ISIS.E.RB2000188

Data is released under the CC-BY-4.0 license.