Spin polarization mechanisms in early stages of photoinduced charge separation in surface-modified TiO2 nanoparticles

T. Rajh; O. Poluektov; A. A. Dubinski; G. Wiederrecht; M. C. Thurnauer; A. D. Trifunac

doi:10.1016/S0009-2614(01)00733-3

Spin polarization mechanisms in early stages of photoinduced charge separation in surface-modified TiO₂ nanoparticles

T. Rajh, O. Poluektov, A. A. Dubinski, G. Wiederrecht, M. C. Thurnauer, A. D. Trifunac

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50 Scopus citations

Abstract

Steady-state and time-resolved electron paramagnetic resonance (EPR) experiments reveal that photoinduced charge separation in surface-modified nanoparticles yields interacting electron-hole radical pairs with spectral features indicative of a range of dynamic properties (Radical Pair Model and emissive Triplet Model CIDEP). Fast exchange in the radical pair is indicated by the presence of a central line at the midpoint, (g_ave=(g_h+g_e)/2) , of electron and hole g-factors. Excess emission is consistent with the triplet character of the exciton precursor. A subset of electron-hole radical pairs exhibits the spin feature characteristic of correlated radical pair polarization (CRPP) reflecting a weak interaction between photogenerated holes and electrons.

Original language	English (US)
Pages (from-to)	31-39
Number of pages	9
Journal	Chemical Physics Letters
Volume	344
Issue number	1-2
DOIs	https://doi.org/10.1016/S0009-2614(01)00733-3
State	Published - Aug 17 2001
Externally published	Yes

ASJC Scopus subject areas

General Physics and Astronomy
Physical and Theoretical Chemistry

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10.1016/S0009-2614(01)00733-3

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@article{ec2fb9672d3f45e3a374041b33b0bf20,

title = "Spin polarization mechanisms in early stages of photoinduced charge separation in surface-modified TiO2 nanoparticles",

abstract = "Steady-state and time-resolved electron paramagnetic resonance (EPR) experiments reveal that photoinduced charge separation in surface-modified nanoparticles yields interacting electron-hole radical pairs with spectral features indicative of a range of dynamic properties (Radical Pair Model and emissive Triplet Model CIDEP). Fast exchange in the radical pair is indicated by the presence of a central line at the midpoint, (gave=(gh+ge)/2) , of electron and hole g-factors. Excess emission is consistent with the triplet character of the exciton precursor. A subset of electron-hole radical pairs exhibits the spin feature characteristic of correlated radical pair polarization (CRPP) reflecting a weak interaction between photogenerated holes and electrons.",

author = "T. Rajh and O. Poluektov and Dubinski, {A. A.} and G. Wiederrecht and Thurnauer, {M. C.} and Trifunac, {A. D.}",

note = "Funding Information: This work was supported by the US Department of Energy, Office of Basic Energy Sciences, Division of Chemical Sciences under contract W-31-109-Eng-38. This work benefited from the use of Electron Microscopy Center for Materials Research at ANL. AAD was supported by the Russian Foundation of Basic Researches RFBR, No. 99-03-33252.",

year = "2001",

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doi = "10.1016/S0009-2614(01)00733-3",

language = "English (US)",

volume = "344",

pages = "31--39",

journal = "Chemical Physics Letters",

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T1 - Spin polarization mechanisms in early stages of photoinduced charge separation in surface-modified TiO2 nanoparticles

AU - Rajh, T.

AU - Poluektov, O.

AU - Dubinski, A. A.

AU - Wiederrecht, G.

AU - Thurnauer, M. C.

AU - Trifunac, A. D.

N1 - Funding Information: This work was supported by the US Department of Energy, Office of Basic Energy Sciences, Division of Chemical Sciences under contract W-31-109-Eng-38. This work benefited from the use of Electron Microscopy Center for Materials Research at ANL. AAD was supported by the Russian Foundation of Basic Researches RFBR, No. 99-03-33252.

PY - 2001/8/17

Y1 - 2001/8/17

N2 - Steady-state and time-resolved electron paramagnetic resonance (EPR) experiments reveal that photoinduced charge separation in surface-modified nanoparticles yields interacting electron-hole radical pairs with spectral features indicative of a range of dynamic properties (Radical Pair Model and emissive Triplet Model CIDEP). Fast exchange in the radical pair is indicated by the presence of a central line at the midpoint, (gave=(gh+ge)/2) , of electron and hole g-factors. Excess emission is consistent with the triplet character of the exciton precursor. A subset of electron-hole radical pairs exhibits the spin feature characteristic of correlated radical pair polarization (CRPP) reflecting a weak interaction between photogenerated holes and electrons.

AB - Steady-state and time-resolved electron paramagnetic resonance (EPR) experiments reveal that photoinduced charge separation in surface-modified nanoparticles yields interacting electron-hole radical pairs with spectral features indicative of a range of dynamic properties (Radical Pair Model and emissive Triplet Model CIDEP). Fast exchange in the radical pair is indicated by the presence of a central line at the midpoint, (gave=(gh+ge)/2) , of electron and hole g-factors. Excess emission is consistent with the triplet character of the exciton precursor. A subset of electron-hole radical pairs exhibits the spin feature characteristic of correlated radical pair polarization (CRPP) reflecting a weak interaction between photogenerated holes and electrons.

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DO - 10.1016/S0009-2614(01)00733-3

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VL - 344

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EP - 39

JO - Chemical Physics Letters

JF - Chemical Physics Letters

IS - 1-2

ER -

Spin polarization mechanisms in early stages of photoinduced charge separation in surface-modified TiO₂ nanoparticles

Abstract

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