Dual lattice incommensurabilities and enhanced lattice perfection by low-temperature thermal annealing in photoelectric (CH3NH3)PbBr3
Type
ArticleAuthors
Li, Wen-Hsien
Lee, Chi-Hung
Ling, Tsu-Yin
Ma, Ma-Hsuan
Wei, Pai-Chun
He, Jr-Hau

Wu, Chun-Min
Peng, Jen-Chih
Xu, Guangyong
Zhao, Yang
Lynn, Jeffrey W.

KAUST Department
Electrical Engineering ProgramKAUST Solar Center (KSC)
Nano Energy Lab
Physical Science and Engineering (PSE) Division
Date
2021-02-01Submitted Date
2020-10-07Permanent link to this record
http://hdl.handle.net/10754/667599
Metadata
Show full item recordAbstract
The coupling between the organic CH3NH3+ cations and inorganic perovskite PbBr3– framework in a large single crystal of (CH3NH3)PbBr3 weighing 13 g was studied using neutron diffraction and inelastic neutron scattering. Two lattice incommensurate (ICM) phases were found; one at higher temperatures, marked ICMHT, appeared between 150 and 134 K. The second one, marked ICMLT, developed below 143 K and remained at 75 K. The transition from the ICMLT to ICMHT phase upon warming gave rise to extremely large lattice shrinking, followed by extremely large lattice expansion of the tetragonal basal plane of the PbBr3 lattice. There was a progressive decrease in the width of the diffuse peak at the Bragg position from the PbBr3– lattice upon warming, which can be described using a critical exponent to show complete ordering of the atoms into a (CH3NH3 )PbBr3 lattice at 200 K. (CH3NH3 )PbBr3 exhibits six definitive acousticlike phonon branches at 75 K. The six branches reconstruct into two at 200 K, with the frequencies of both the transverse and longitudinal modes greatly enhanced. The asymmetric structure of the CH3NH3 ions together with the indirect interactions between the CH3NH3 ions mediated through the Br ions are used to understand the observed behaviors.Citation
Li, W.-H., Lee, C.-H., Ling, T.-Y., Ma, M.-H., Wei, P.-C., He, J.-H., … Lynn, J. W. (2021). Dual lattice incommensurabilities and enhanced lattice perfection by low-temperature thermal annealing in photoelectric (CH3NH3)PbBr3. Physical Review Materials, 5(2). doi:10.1103/physrevmaterials.5.025401Sponsors
This work was supported by the Ministry of Science and Technology, Taiwan under Grant No. MOST 109-2112-M-008-027. We acknowledge the Ministry of Science and Technology, Taiwan for financial support through Grant No. MOST-108-2739-M-213-001 from the National Synchrotron Radiation Research Center (NSRRC) Neutron Cultivation Program, and for providing the neutron scattering facility used in this work.Publisher
American Physical Society (APS)Journal
Physical Review MaterialsAdditional Links
https://link.aps.org/doi/10.1103/PhysRevMaterials.5.025401ae974a485f413a2113503eed53cd6c53
10.1103/physrevmaterials.5.025401