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Free Carriers versus Self-Trapped Excitons at Different Facets of Ruddlesden-Popper Two-Dimensional Lead Halide Perovskite Single Crystals

Liang, Mingli LU ; Lin, Weihua LU ; Zhao, Qian ; Zou, Xianshao LU ; Lan, Zhenyun ; Meng, Jie ; Shi, Qi LU ; Castelli, Ivano E. ; Canton, Sophie E. LU and Pullerits, Tönu LU , et al. (2021) In Journal of Physical Chemistry Letters 12(20). p.4965-4971
Abstract

The physical origin of sub-band gap photoluminescence in Ruddlesden-Poppers two-dimensional (2D) lead halide perovskites (LHPs) is still under debate. In this paper, we studied the photoluminescence features from two different facets of 2D LHP single crystals: the in-plane facet (IF) containing the 2D inorganic layers and the facet perpendicular to the 2D layers (PF). At the IF, the free carriers (FCs) dominate due to the weak electron-phonon coupling in a symmetric lattice. At the PF, the strain accumulation along the 2D layers enhances the electron-phonon coupling and facilitates self-trapped exciton (STE) formation. The time-resolved PL studies indicate that free carriers (FCs) at the IF can move freely and display the trapping by... (More)

The physical origin of sub-band gap photoluminescence in Ruddlesden-Poppers two-dimensional (2D) lead halide perovskites (LHPs) is still under debate. In this paper, we studied the photoluminescence features from two different facets of 2D LHP single crystals: the in-plane facet (IF) containing the 2D inorganic layers and the facet perpendicular to the 2D layers (PF). At the IF, the free carriers (FCs) dominate due to the weak electron-phonon coupling in a symmetric lattice. At the PF, the strain accumulation along the 2D layers enhances the electron-phonon coupling and facilitates self-trapped exciton (STE) formation. The time-resolved PL studies indicate that free carriers (FCs) at the IF can move freely and display the trapping by the intrinsic defects. The STEs at the PF are not likely trapped by the defects due to the reduced mobility. However, with increasing STE density, the STE transport is promoted, enabling the trapping of STE by the intrinsic defects.

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organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of Physical Chemistry Letters
volume
12
issue
20
pages
7 pages
publisher
The American Chemical Society (ACS)
external identifiers
  • scopus:85107085166
  • pmid:34014103
ISSN
1948-7185
DOI
10.1021/acs.jpclett.1c01148
language
English
LU publication?
yes
id
3075cc3f-6c29-48d2-bb5a-164ea3fc0ac6
date added to LUP
2021-12-27 13:31:32
date last changed
2024-06-15 23:18:34
@article{3075cc3f-6c29-48d2-bb5a-164ea3fc0ac6,
  abstract     = {{<p>The physical origin of sub-band gap photoluminescence in Ruddlesden-Poppers two-dimensional (2D) lead halide perovskites (LHPs) is still under debate. In this paper, we studied the photoluminescence features from two different facets of 2D LHP single crystals: the in-plane facet (IF) containing the 2D inorganic layers and the facet perpendicular to the 2D layers (PF). At the IF, the free carriers (FCs) dominate due to the weak electron-phonon coupling in a symmetric lattice. At the PF, the strain accumulation along the 2D layers enhances the electron-phonon coupling and facilitates self-trapped exciton (STE) formation. The time-resolved PL studies indicate that free carriers (FCs) at the IF can move freely and display the trapping by the intrinsic defects. The STEs at the PF are not likely trapped by the defects due to the reduced mobility. However, with increasing STE density, the STE transport is promoted, enabling the trapping of STE by the intrinsic defects. </p>}},
  author       = {{Liang, Mingli and Lin, Weihua and Zhao, Qian and Zou, Xianshao and Lan, Zhenyun and Meng, Jie and Shi, Qi and Castelli, Ivano E. and Canton, Sophie E. and Pullerits, Tönu and Zheng, Kaibo}},
  issn         = {{1948-7185}},
  language     = {{eng}},
  number       = {{20}},
  pages        = {{4965--4971}},
  publisher    = {{The American Chemical Society (ACS)}},
  series       = {{Journal of Physical Chemistry Letters}},
  title        = {{Free Carriers versus Self-Trapped Excitons at Different Facets of Ruddlesden-Popper Two-Dimensional Lead Halide Perovskite Single Crystals}},
  url          = {{http://dx.doi.org/10.1021/acs.jpclett.1c01148}},
  doi          = {{10.1021/acs.jpclett.1c01148}},
  volume       = {{12}},
  year         = {{2021}},
}