Ultrafast Carrier Trapping of a Metal-Doped Titanium Dioxide Semiconductor Revealed by Femtosecond Transient Absorption Spectroscopy

Handle URI:
http://hdl.handle.net/10754/556649
Title:
Ultrafast Carrier Trapping of a Metal-Doped Titanium Dioxide Semiconductor Revealed by Femtosecond Transient Absorption Spectroscopy
Authors:
Sun, Jingya; Yang, Yang; Khan, Jafar I.; Alarousu, Erkki; Guo, Zaibing; Zhang, Xixiang ( 0000-0002-3478-6414 ) ; Zhang, Qiang; Mohammed, Omar F. ( 0000-0001-8500-1130 )
Abstract:
We explored for the first time the ultrafast carrier trapping of a metal-doped titanium dioxide (TiO2) semiconductor using broad-band transient absorption (TA) spectroscopy with 120 fs temporal resolution. Titanium dioxide was successfully doped layer-by-layer with two metal ions, namely tungsten and cobalt. The time-resolved data demonstrate clearly that the carrier trapping time decreases progressively as the doping concentration increases. A global-fitting procedure for the carrier trapping suggests the appearance of two time components: a fast one that is directly associated with carrier trapping to the defect state in the vicinity of the conduction band and a slow one that is attributed to carrier trapping to the deep-level state from the conduction band. With a relatively long doping deposition time on the order of 30 s, a carrier lifetime of about 1 ps is obtained. To confirm that the measured ultrafast carrier dynamics are associated with electron trapping by metal doping, we explored the carrier dynamics of undoped TiO2. The findings reported here may be useful for the implementation of high-speed optoelectronic applications and fast switching devices.
KAUST Department:
Physical Sciences and Engineering (PSE) Division; Solar and Photovoltaic Engineering Research Center (SPERC); Advanced Nanofabrication and Thin Film Core Lab; Imaging and Characterization Core Lab
Citation:
Ultrafast Carrier Trapping of a Metal-Doped Titanium Dioxide Semiconductor Revealed by Femtosecond Transient Absorption Spectroscopy 2014, 6 (13):10022 ACS Applied Materials & Interfaces
Publisher:
American Chemical Society (ACS)
Journal:
ACS Applied Materials & Interfaces
Issue Date:
11-Jun-2014
DOI:
10.1021/am5026159
Type:
Article
ISSN:
1944-8244; 1944-8252
Additional Links:
http://pubs.acs.org/doi/abs/10.1021/am5026159
Appears in Collections:
Articles; Advanced Nanofabrication, Imaging and Characterization Core Lab; Physical Sciences and Engineering (PSE) Division; Solar and Photovoltaic Engineering Research Center (SPERC)

Full metadata record

DC FieldValue Language
dc.contributor.authorSun, Jingyaen
dc.contributor.authorYang, Yangen
dc.contributor.authorKhan, Jafar I.en
dc.contributor.authorAlarousu, Erkkien
dc.contributor.authorGuo, Zaibingen
dc.contributor.authorZhang, Xixiangen
dc.contributor.authorZhang, Qiangen
dc.contributor.authorMohammed, Omar F.en
dc.date.accessioned2015-06-10T11:40:09Zen
dc.date.available2015-06-10T11:40:09Zen
dc.date.issued2014-06-11en
dc.identifier.citationUltrafast Carrier Trapping of a Metal-Doped Titanium Dioxide Semiconductor Revealed by Femtosecond Transient Absorption Spectroscopy 2014, 6 (13):10022 ACS Applied Materials & Interfacesen
dc.identifier.issn1944-8244en
dc.identifier.issn1944-8252en
dc.identifier.doi10.1021/am5026159en
dc.identifier.urihttp://hdl.handle.net/10754/556649en
dc.description.abstractWe explored for the first time the ultrafast carrier trapping of a metal-doped titanium dioxide (TiO2) semiconductor using broad-band transient absorption (TA) spectroscopy with 120 fs temporal resolution. Titanium dioxide was successfully doped layer-by-layer with two metal ions, namely tungsten and cobalt. The time-resolved data demonstrate clearly that the carrier trapping time decreases progressively as the doping concentration increases. A global-fitting procedure for the carrier trapping suggests the appearance of two time components: a fast one that is directly associated with carrier trapping to the defect state in the vicinity of the conduction band and a slow one that is attributed to carrier trapping to the deep-level state from the conduction band. With a relatively long doping deposition time on the order of 30 s, a carrier lifetime of about 1 ps is obtained. To confirm that the measured ultrafast carrier dynamics are associated with electron trapping by metal doping, we explored the carrier dynamics of undoped TiO2. The findings reported here may be useful for the implementation of high-speed optoelectronic applications and fast switching devices.en
dc.publisherAmerican Chemical Society (ACS)en
dc.relation.urlhttp://pubs.acs.org/doi/abs/10.1021/am5026159en
dc.rightsThis document is the Accepted Manuscript version of a Published Work that appeared in final form in ACS Applied Materials & Interfaces, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://pubs.acs.org/doi/abs/10.1021/am5026159.en
dc.subjectultrafast carrier trappingen
dc.subjecttitanium dioxideen
dc.subjecttransient absorption spectroscopyen
dc.subjectmetal-dopeden
dc.subjectdeep-level stateen
dc.titleUltrafast Carrier Trapping of a Metal-Doped Titanium Dioxide Semiconductor Revealed by Femtosecond Transient Absorption Spectroscopyen
dc.typeArticleen
dc.contributor.departmentPhysical Sciences and Engineering (PSE) Divisionen
dc.contributor.departmentSolar and Photovoltaic Engineering Research Center (SPERC)en
dc.contributor.departmentAdvanced Nanofabrication and Thin Film Core Laben
dc.contributor.departmentImaging and Characterization Core Laben
dc.identifier.journalACS Applied Materials & Interfacesen
dc.eprint.versionPost-printen
kaust.authorYang, Yangen
kaust.authorGuo, Zaibingen
kaust.authorZhang, Xixiangen
kaust.authorZhang, Qiangen
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