Abstract
The most common material for dye-sensitized photocathodes is mesoporous NiO. We transformed the usual brownish NiO to be more transparent by reducing high valence Ni impurities. Two pretreatment methods have been used: Chemical reduction by NaBH4 and thermal reduction by heating. The power conversion efficiency of the cell was increased by 33% through chemical treatment, and an increase in open-circuit voltage from 105 to 225 mV was obtained upon heat treatment. By optical spectroelectrochemistry, we could identify two species with characteristically different spectra assigned to Ni3+ and Ni4+. We suggest that the reduction of surface Ni3+ and Ni4+ to Ni decreases the recombination reaction between holes on the NiO surface with the electrolyte. It also keeps the dye firmly on the surface, building a barrier for electrolyte recombination. This causes an increase in open-circuit photovoltage for the treated film.
| Original language | English |
|---|---|
| Pages (from-to) | 33470-33477 |
| Number of pages | 8 |
| Journal | ACS Applied Materials and Interfaces |
| Volume | 9 |
| Issue number | 39 |
| DOIs | |
| Publication status | Published - Jan 1 2017 |
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Keywords
- Characterization
- Dye-sensitized solar cell
- Hole UV-vis spectrum
- P-type
- Photovoltage
- Recombination
ASJC Scopus subject areas
- Materials Science(all)
Cite this
Chemical and physical reduction of high valence ni states in mesoporous Nio film for solar cell application. / D'Amario, Luca; Jiang, Roger; Cappel, Ute B.; Gibson, Elizabeth A.; Boschloo, Gerrit; Rensmo, Håkan; Sun, Licheng; Hammarström, Leif; Tian, Haining.
In: ACS Applied Materials and Interfaces, Vol. 9, No. 39, 01.01.2017, p. 33470-33477.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Chemical and physical reduction of high valence ni states in mesoporous Nio film for solar cell application
AU - D'Amario, Luca
AU - Jiang, Roger
AU - Cappel, Ute B.
AU - Gibson, Elizabeth A.
AU - Boschloo, Gerrit
AU - Rensmo, Håkan
AU - Sun, Licheng
AU - Hammarström, Leif
AU - Tian, Haining
PY - 2017/1/1
Y1 - 2017/1/1
N2 - The most common material for dye-sensitized photocathodes is mesoporous NiO. We transformed the usual brownish NiO to be more transparent by reducing high valence Ni impurities. Two pretreatment methods have been used: Chemical reduction by NaBH4 and thermal reduction by heating. The power conversion efficiency of the cell was increased by 33% through chemical treatment, and an increase in open-circuit voltage from 105 to 225 mV was obtained upon heat treatment. By optical spectroelectrochemistry, we could identify two species with characteristically different spectra assigned to Ni3+ and Ni4+. We suggest that the reduction of surface Ni3+ and Ni4+ to Ni decreases the recombination reaction between holes on the NiO surface with the electrolyte. It also keeps the dye firmly on the surface, building a barrier for electrolyte recombination. This causes an increase in open-circuit photovoltage for the treated film.
AB - The most common material for dye-sensitized photocathodes is mesoporous NiO. We transformed the usual brownish NiO to be more transparent by reducing high valence Ni impurities. Two pretreatment methods have been used: Chemical reduction by NaBH4 and thermal reduction by heating. The power conversion efficiency of the cell was increased by 33% through chemical treatment, and an increase in open-circuit voltage from 105 to 225 mV was obtained upon heat treatment. By optical spectroelectrochemistry, we could identify two species with characteristically different spectra assigned to Ni3+ and Ni4+. We suggest that the reduction of surface Ni3+ and Ni4+ to Ni decreases the recombination reaction between holes on the NiO surface with the electrolyte. It also keeps the dye firmly on the surface, building a barrier for electrolyte recombination. This causes an increase in open-circuit photovoltage for the treated film.
KW - Characterization
KW - Dye-sensitized solar cell
KW - Hole UV-vis spectrum
KW - P-type
KW - Photovoltage
KW - Recombination
UR - http://www.scopus.com/inward/record.url?scp=85027407005&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85027407005&partnerID=8YFLogxK
U2 - 10.1021/acsami.7b01532
DO - 10.1021/acsami.7b01532
M3 - Article
AN - SCOPUS:85027407005
VL - 9
SP - 33470
EP - 33477
JO - ACS applied materials & interfaces
JF - ACS applied materials & interfaces
SN - 1944-8244
IS - 39
ER -