liu.seSök publikationer i DiVA
Ändra sökning
RefereraExporteraLänk till posten
Permanent länk

Direktlänk
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Charge carrier dynamics in tantalum oxide overlayered and tantalum doped hematite photoanodes
Linköpings universitet, Institutionen för teknik och naturvetenskap, Laboratoriet för organisk elektronik. Linköpings universitet, Tekniska fakulteten. Chemistry and Advanced Materials, Laboratory of Chemistry and Bioengineering,Tampere University of Technology, Tampere, Finland..ORCID-id: 0000-0003-3091-1051
Tampere Univ Technol, Finland.
Univ Helsinki, Finland.
Tampere Univ Technol, Finland.
Visa övriga samt affilieringar
2019 (Engelska)Ingår i: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 7, nr 7, s. 3206-3215Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

We employ atomic layer deposition to prepare 50 nm thick hematite photoanodes followed by passivating them with a 0.5 nm thick Ta2O5-overlayer and compare them with samples uniformly doped with the same amount of tantalum. We observe a three-fold improvement in photocurrent with the same onset voltage using Ta-overlayer hematite photoanodes, while electrochemical impedance spectroscopy under visible light irradiation shows a decreased amount of surface states under water splitting conditions. The Tadoped samples have an even higher increase in photocurrent along with a 0.15 V cathodic shift in the onset voltage and decreased resistivity. However, the surface state capacitance for the Ta-doped sample is twice that of the reference photoanode, which implies a larger amount of surface hole accumulation. We further utilize transient absorption spectroscopy in the sub-millisecond to second timescale under operating conditions to show that electron trapping in both Ta2O5-passivated and Ta-doped samples is markedly reduced. Ultrafast transient absorption spectroscopy in the sub-picosecond to nanosecond timescale shows faster charge carrier dynamics and reduced recombination in the Ta-doped hematite photoanode resulting in the increased photoelectrochemical performance when compared with the Ta2O5-overlayer sample. Our results show that passivation does not affect the poor charge carrier dynamics intrinsic to hematite based photoanodes. The Ta-doping strategy results in more efficient electron extraction, solving the electron trapping issue and leading to increased performance over the surface passivation strategy.

Ort, förlag, år, upplaga, sidor
ROYAL SOC CHEMISTRY , 2019. Vol. 7, nr 7, s. 3206-3215
Nationell ämneskategori
Materialkemi
Identifikatorer
URN: urn:nbn:se:liu:diva-154835DOI: 10.1039/c8ta09501aISI: 000458682100026OAI: oai:DiVA.org:liu-154835DiVA, id: diva2:1294595
Anmärkning

Funding Agencies|Finnish Cultural Foundation; Jenny and Antti Wihuri Foundation; Academy of Finland [141481, 286713, 309920]; Finnish Centre of Excellence in Atomic Layer Deposition

Tillgänglig från: 2019-03-07 Skapad: 2019-03-07 Senast uppdaterad: 2019-09-23Bibliografiskt granskad

Open Access i DiVA

fulltext(1538 kB)104 nedladdningar
Filinformation
Filnamn FULLTEXT01.pdfFilstorlek 1538 kBChecksumma SHA-512
38fd2246a7aba75bbf151694211423c56b1e5ad1853624361dcbe26869e00a0fd846c97029274a121b190e2090433662c8226bd47df39a295394f1b423d52144
Typ fulltextMimetyp application/pdf

Övriga länkar

Förlagets fulltext

Personposter BETA

Ruoko, Tero-Petri

Sök vidare i DiVA

Av författaren/redaktören
Ruoko, Tero-Petri
Av organisationen
Laboratoriet för organisk elektronikTekniska fakulteten
I samma tidskrift
Journal of Materials Chemistry A
Materialkemi

Sök vidare utanför DiVA

GoogleGoogle Scholar
Totalt: 104 nedladdningar
Antalet nedladdningar är summan av nedladdningar för alla fulltexter. Det kan inkludera t.ex tidigare versioner som nu inte längre är tillgängliga.

doi
urn-nbn

Altmetricpoäng

doi
urn-nbn
Totalt: 158 träffar
RefereraExporteraLänk till posten
Permanent länk

Direktlänk
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf