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dc.contributor.authorMaity, Partha*
dc.contributor.authorMohammed, Omar F.*
dc.contributor.authorKatsiev, Khabiboulakh*
dc.contributor.authorIdriss, Hicham*
dc.date.accessioned2018-04-16T11:27:44Z
dc.date.available2018-04-16T11:27:44Z
dc.date.issued2018-04-02en
dc.identifier.citationMaity P, Mohammed OF, Katsiev K, Idriss H (2018) Study of the Bulk Charge Carrier Dynamics in Anatase and Rutile TiO2 Single Crystals by Femtosecond Time-Resolved Spectroscopy. The Journal of Physical Chemistry C. Available: http://dx.doi.org/10.1021/acs.jpcc.8b00256.en
dc.identifier.issn1932-7447en
dc.identifier.issn1932-7455en
dc.identifier.doi10.1021/acs.jpcc.8b00256en
dc.identifier.urihttp://hdl.handle.net/10754/627541
dc.description.abstractUnderstanding of the fundamentals behind charge carriers of photo-catalytic materials are still illusive hindering progress in our quest for renewable energy. TiO2 anatase and rutile are the most understood phases in photo-catalysis and serve as the best model for fundamental studies. Their ultrafast charge carrier dynamics especially on TiO2 anatase single crystal (the most active phase) are unresolved. Here femtosecond time resolved spectroscopy (TRS) was carried out to explore the dynamics of photo-excited charge carriers’ recombination in anatase single crystal, for the first time using pump fluence effects, and compares it to that of the rutile single crystal. A significant difference in charge carrier recombination rates between both crystals is observed. We found that the time constants for carrier recombination are two orders of magnitude slower for anatase (101) when compared to those of rutile (110). Moreover, bulk defects introduced by reduction of the samples via annealing in ultra-high vacuum resulted in faster recombination rates for both polymorphs. Both states (fresh and reduced) probed by pump fluence dependence measurements revealed that the major recombination channel in fresh and reduced anatase and reduced rutile is the first-order Shockley–Reed mediated. However, for fresh rutile, third-body Auger recombination was observed, attributed to the presence of higher density of intrinsic charge carriers. At all excitation wavelengths and fluence investigated, anatase (101) single crystal show longer charge carrier lifetime when compared to rutile (110) single. This may explain the superiority of the anatase phase for the electron transfer H+ reduction to molecular hydrogen.en
dc.publisherAmerican Chemical Society (ACS)en
dc.relation.urlhttps://pubs.acs.org/doi/10.1021/acs.jpcc.8b00256en
dc.rightsThis document is the Accepted Manuscript version of a Published Work that appeared in final form in The Journal of Physical Chemistry C, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://pubs.acs.org/doi/10.1021/acs.jpcc.8b00256.en
dc.titleStudy of the Bulk Charge Carrier Dynamics in Anatase and Rutile TiO2 Single Crystals by Femtosecond Time Resolved Spectroscopyen
dc.typeArticleen
dc.contributor.departmentKAUST Solar Center (KSC)*
dc.contributor.departmentPhysical Sciences and Engineering (PSE) Division*
dc.contributor.departmentChemical Science Program*
dc.contributor.departmentSABIC - Corporate Research and Innovation Center (CRI) at KAUST*
dc.identifier.journalThe Journal of Physical Chemistry Cen
dc.eprint.versionPost-printen
kaust.authorMaity, Partha*
kaust.authorMohammed, Omar F.*
kaust.authorKatsiev, Khabiboulakh*
kaust.authorIdriss, Hicham*


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