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Alkali Salts as Interface Modifiers in n-i-p Hybrid Perovskite Solar Cells

Dagar, Janardan ; Hirselandt, Katrin ; Merdasa, Aboma LU ; Czudek, Aniela ; Munir, Rahim ; Zu, Fengshuo ; Koch, Norbert ; Dittrich, Thomas and Unger, Eva L. LU (2019) In Solar RRL 3(9).
Abstract

After demonstration of a 23% power conversion efficiency, a high operational stability is the next most important scientific and technological challenge in perovskite solar cells (PSCs). A potential failure mechanism is tied to a bias-induced ion migration, which causes current–voltage hysteresis and a decay in the device performance over time. Herein, alkali salts are shown to mitigate hysteresis and stabilize device performance in n-i-p hybrid planar PSCs. Different alkali salts of potassium chloride, iodide, and nitrate as well as sodium chloride and iodide are deposited from aqueous solution onto the n-type contact, based on SnO2, prior to deposition of the perovskite absorber... (More)

After demonstration of a 23% power conversion efficiency, a high operational stability is the next most important scientific and technological challenge in perovskite solar cells (PSCs). A potential failure mechanism is tied to a bias-induced ion migration, which causes current–voltage hysteresis and a decay in the device performance over time. Herein, alkali salts are shown to mitigate hysteresis and stabilize device performance in n-i-p hybrid planar PSCs. Different alkali salts of potassium chloride, iodide, and nitrate as well as sodium chloride and iodide are deposited from aqueous solution onto the n-type contact, based on SnO2, prior to deposition of the perovskite absorber Cs0.05(FA0.83MA0.17)0.95Pb(I0.83Br0.17)3. Introduction of potassium-based alkali salts suppresses the current–voltage hysteresis and stabilizes the operational device stability at the maximum power point. This is attributed to the suppression of hole trapping at the n-type selective transport layer (SnO2)/perovskite interface observed by surface photovoltage spectroscopy, which is interpreted to reduce interfacial recombination and improve charge carrier extraction. The best and most stable performance of 19% is achieved using potassium nitrate as the interface modifier. Devices with higher and more stable performance exhibit substantially lower current transients, analyzed during maximum power point tracking.

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author
; ; ; ; ; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
alkali salts, interface modification, n-i-p devices, perovskite solar cells
in
Solar RRL
volume
3
issue
9
article number
1900088
publisher
Wiley-VCH Verlag
external identifiers
  • scopus:85083623216
ISSN
2367-198X
DOI
10.1002/solr.201900088
language
English
LU publication?
yes
id
fb2f1a41-8190-4944-85c2-09b39436a9e9
date added to LUP
2020-06-05 11:15:21
date last changed
2020-10-07 06:59:41
@article{fb2f1a41-8190-4944-85c2-09b39436a9e9,
  abstract     = {<p>After demonstration of a 23% power conversion efficiency, a high operational stability is the next most important scientific and technological challenge in perovskite solar cells (PSCs). A potential failure mechanism is tied to a bias-induced ion migration, which causes current–voltage hysteresis and a decay in the device performance over time. Herein, alkali salts are shown to mitigate hysteresis and stabilize device performance in n-i-p hybrid planar PSCs. Different alkali salts of potassium chloride, iodide, and nitrate as well as sodium chloride and iodide are deposited from aqueous solution onto the n-type contact, based on SnO<sub>2</sub>, prior to deposition of the perovskite absorber Cs<sub>0.05</sub>(FA<sub>0.83</sub>MA<sub>0.17</sub>)<sub>0.95</sub>Pb(I<sub>0.83</sub>Br<sub>0.17</sub>)<sub>3</sub>. Introduction of potassium-based alkali salts suppresses the current–voltage hysteresis and stabilizes the operational device stability at the maximum power point. This is attributed to the suppression of hole trapping at the n-type selective transport layer (SnO<sub>2</sub>)/perovskite interface observed by surface photovoltage spectroscopy, which is interpreted to reduce interfacial recombination and improve charge carrier extraction. The best and most stable performance of 19% is achieved using potassium nitrate as the interface modifier. Devices with higher and more stable performance exhibit substantially lower current transients, analyzed during maximum power point tracking.</p>},
  author       = {Dagar, Janardan and Hirselandt, Katrin and Merdasa, Aboma and Czudek, Aniela and Munir, Rahim and Zu, Fengshuo and Koch, Norbert and Dittrich, Thomas and Unger, Eva L.},
  issn         = {2367-198X},
  language     = {eng},
  number       = {9},
  publisher    = {Wiley-VCH Verlag},
  series       = {Solar RRL},
  title        = {Alkali Salts as Interface Modifiers in n-i-p Hybrid Perovskite Solar Cells},
  url          = {http://dx.doi.org/10.1002/solr.201900088},
  doi          = {10.1002/solr.201900088},
  volume       = {3},
  year         = {2019},
}