Alkali Salts as Interface Modifiers in n-i-p Hybrid Perovskite Solar Cells
(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. (Less)
- author
- 						Dagar, Janardan
	; 						Hirselandt, Katrin
	; 						Merdasa, Aboma
				LU
				 ; 						Czudek, Aniela
	; 						Munir, Rahim
	; 						Zu, Fengshuo
	; 						Koch, Norbert
	; 						Dittrich, Thomas
	 and 						Unger, Eva L.
				LU ; 						Czudek, Aniela
	; 						Munir, Rahim
	; 						Zu, Fengshuo
	; 						Koch, Norbert
	; 						Dittrich, Thomas
	 and 						Unger, Eva L.
				LU
- organization
- publishing date
- 2019-09
- 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
- 2025-10-14 12:30:33
@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}},
  keywords     = {{alkali salts; interface modification; n-i-p devices; perovskite solar cells}},
  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}},
}