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Mechanism of Charge Transfer and Recombination Dynamics in Organo Metal Halide Perovskites and Organic Electrodes, PCBM, and Spiro-OMeTAD: Role of Dark Carriers.

Ponseca, Carlito LU ; Hutter, Eline M; Piatkowski, Piotr; Cohen, Boiko; Pascher, Torbjörn LU ; Douhal, Abderrazzak; Yartsev, Arkady LU ; Sundström, Villy LU and Savenije, Tom J (2015) In Journal of the American Chemical Society 137(51). p.16043-16048
Abstract
Despite the unprecedented interest in organic-inorganic metal halide perovskite solar cells, quantitative information on the charge transfer dynamics into selective electrodes is still lacking. In this paper, we report the time scales and mechanisms of electron and hole injection and recombination dynamics at organic PCBM and Spiro-OMeTAD electrode interfaces. On the one hand, hole transfer is complete on the subpicosecond time scale in MAPbI3/Spiro-OMeTAD, and its recombination rate is similar to that in neat MAPbI3. This was found to be due to a high concentration of dark charges, i.e., holes brought about by unintentional p-type doping of MAPbI3. Hence, the total concentration of holes in the perovskite is hardly affected by optical... (More)
Despite the unprecedented interest in organic-inorganic metal halide perovskite solar cells, quantitative information on the charge transfer dynamics into selective electrodes is still lacking. In this paper, we report the time scales and mechanisms of electron and hole injection and recombination dynamics at organic PCBM and Spiro-OMeTAD electrode interfaces. On the one hand, hole transfer is complete on the subpicosecond time scale in MAPbI3/Spiro-OMeTAD, and its recombination rate is similar to that in neat MAPbI3. This was found to be due to a high concentration of dark charges, i.e., holes brought about by unintentional p-type doping of MAPbI3. Hence, the total concentration of holes in the perovskite is hardly affected by optical excitation, which manifested as similar decay kinetics. On the other hand, the decay of the photoinduced conductivity in MAPbI3/PCBM is on the time scale of hundreds of picoseconds to several nanoseconds, due to electron injection into PCBM and electron-hole recombination at the interface occurring at similar rates. These results highlight the importance of understanding the role of dark carriers in deconvoluting the complex photophysical processes in these materials. Moreover, optimizing the preparation processes wherein undesired doping is minimized could prompt the use of organic molecules as a more viable electrode substitute for perovskite solar cell devices. (Less)
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organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of the American Chemical Society
volume
137
issue
51
pages
16043 - 16048
publisher
The American Chemical Society
external identifiers
  • pmid:26636183
  • wos:000367636600016
  • scopus:84953439955
ISSN
1520-5126
DOI
10.1021/jacs.5b08770
language
English
LU publication?
yes
id
f04f9997-83f6-49bb-85b8-b431cf903e55 (old id 8505652)
date added to LUP
2016-01-08 10:50:17
date last changed
2017-10-29 03:23:58
@article{f04f9997-83f6-49bb-85b8-b431cf903e55,
  abstract     = {Despite the unprecedented interest in organic-inorganic metal halide perovskite solar cells, quantitative information on the charge transfer dynamics into selective electrodes is still lacking. In this paper, we report the time scales and mechanisms of electron and hole injection and recombination dynamics at organic PCBM and Spiro-OMeTAD electrode interfaces. On the one hand, hole transfer is complete on the subpicosecond time scale in MAPbI3/Spiro-OMeTAD, and its recombination rate is similar to that in neat MAPbI3. This was found to be due to a high concentration of dark charges, i.e., holes brought about by unintentional p-type doping of MAPbI3. Hence, the total concentration of holes in the perovskite is hardly affected by optical excitation, which manifested as similar decay kinetics. On the other hand, the decay of the photoinduced conductivity in MAPbI3/PCBM is on the time scale of hundreds of picoseconds to several nanoseconds, due to electron injection into PCBM and electron-hole recombination at the interface occurring at similar rates. These results highlight the importance of understanding the role of dark carriers in deconvoluting the complex photophysical processes in these materials. Moreover, optimizing the preparation processes wherein undesired doping is minimized could prompt the use of organic molecules as a more viable electrode substitute for perovskite solar cell devices.},
  author       = {Ponseca, Carlito and Hutter, Eline M and Piatkowski, Piotr and Cohen, Boiko and Pascher, Torbjörn and Douhal, Abderrazzak and Yartsev, Arkady and Sundström, Villy and Savenije, Tom J},
  issn         = {1520-5126},
  language     = {eng},
  number       = {51},
  pages        = {16043--16048},
  publisher    = {The American Chemical Society},
  series       = {Journal of the American Chemical Society},
  title        = {Mechanism of Charge Transfer and Recombination Dynamics in Organo Metal Halide Perovskites and Organic Electrodes, PCBM, and Spiro-OMeTAD: Role of Dark Carriers.},
  url          = {http://dx.doi.org/10.1021/jacs.5b08770},
  volume       = {137},
  year         = {2015},
}