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High Excitation Intensity Opens a New Trapping Channel in Organic–Inorganic Hybrid Perovskite Nanoparticles.

Zheng, Kaibo LU ; Zidek, Karel LU ; Abdellah, Mohamed LU ; Chen, Junsheng LU ; Chabera, Pavel LU ; Zhang, Wei ; Al-Marri, Mohammed J. and Pullerits, Tönu LU (2016) In ACS Energy Letters 1(6). p.1154-1161
Abstract
We investigated the excited-state dynamics of CH3NH3PbBr3 perovskite nanoparticles (NPs) and bulk crystals under various excitation intensity regimes using transient absorption spectroscopy. We confirmed the sub-band gap hole trap states with optical transition to the conduction band in both samples. In bulk crystals, the excited-state dynamics is independent of pump intensity. However, in NPs, pronounced intensity dependence appears. At low intensities, the hole trap states do not affect the excited-state dynamics due to the potential barrier between the photogenerated holes and the surface trap states. When the excitation density is much higher than one per NP, charge accumulation makes hot holes overcome the barrier and get trapped with... (More)
We investigated the excited-state dynamics of CH3NH3PbBr3 perovskite nanoparticles (NPs) and bulk crystals under various excitation intensity regimes using transient absorption spectroscopy. We confirmed the sub-band gap hole trap states with optical transition to the conduction band in both samples. In bulk crystals, the excited-state dynamics is independent of pump intensity. However, in NPs, pronounced intensity dependence appears. At low intensities, the hole trap states do not affect the excited-state dynamics due to the potential barrier between the photogenerated holes and the surface trap states. When the excitation density is much higher than one per NP, charge accumulation makes hot holes overcome the barrier and get trapped with electrons long living in the conduction band (≫10 ns). This explains the high emissive properties of such NPs despite the existence of surface traps. However, in the application of emitting devices requiring high excitation intensity, the surface trapping becomes significant. (Less)
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author
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organization
publishing date
type
Contribution to journal
publication status
published
subject
in
ACS Energy Letters
volume
1
issue
6
pages
8 pages
publisher
The American Chemical Society (ACS)
external identifiers
  • scopus:85015213173
ISSN
2380-8195
DOI
10.1021/acsenergylett.6b00352
language
English
LU publication?
yes
id
45310149-59fd-457f-8885-1164f0ef08e2
date added to LUP
2019-09-14 14:16:51
date last changed
2023-12-03 23:57:46
@article{45310149-59fd-457f-8885-1164f0ef08e2,
  abstract     = {{We investigated the excited-state dynamics of CH3NH3PbBr3 perovskite nanoparticles (NPs) and bulk crystals under various excitation intensity regimes using transient absorption spectroscopy. We confirmed the sub-band gap hole trap states with optical transition to the conduction band in both samples. In bulk crystals, the excited-state dynamics is independent of pump intensity. However, in NPs, pronounced intensity dependence appears. At low intensities, the hole trap states do not affect the excited-state dynamics due to the potential barrier between the photogenerated holes and the surface trap states. When the excitation density is much higher than one per NP, charge accumulation makes hot holes overcome the barrier and get trapped with electrons long living in the conduction band (≫10 ns). This explains the high emissive properties of such NPs despite the existence of surface traps. However, in the application of emitting devices requiring high excitation intensity, the surface trapping becomes significant.}},
  author       = {{Zheng, Kaibo and Zidek, Karel and Abdellah, Mohamed and Chen, Junsheng and Chabera, Pavel and Zhang, Wei and Al-Marri, Mohammed J. and Pullerits, Tönu}},
  issn         = {{2380-8195}},
  language     = {{eng}},
  number       = {{6}},
  pages        = {{1154--1161}},
  publisher    = {{The American Chemical Society (ACS)}},
  series       = {{ACS Energy Letters}},
  title        = {{High Excitation Intensity Opens a New Trapping Channel in Organic–Inorganic Hybrid Perovskite Nanoparticles.}},
  url          = {{http://dx.doi.org/10.1021/acsenergylett.6b00352}},
  doi          = {{10.1021/acsenergylett.6b00352}},
  volume       = {{1}},
  year         = {{2016}},
}