Intermolecular energy transfer across nanocrystalline semiconductor surfaces

被引:26
作者
Higgins, GT
Bergeron, BV
Hasselmann, GM
Farzad, F
Meyer, GJ [1 ]
机构
[1] Johns Hopkins Univ, Dept Chem, Baltimore, MD 21218 USA
[2] Johns Hopkins Univ, Dept Mat Sci & Engn, Baltimore, MD 21218 USA
关键词
D O I
10.1021/jp0543680
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
The yields and dynamics for energy transfer from the metal-to-ligand charge-transfer excited states of Ru(deeb)(bpy)(2)(PF6)(2), Ru2+, and Os(deeb)(bpy)(2)(PF6)(2), OS2+, where deeb is 4,4'-(CH3CH2CO2)(2)-2,2'-bipyridine, anchored to mesoporous nanocrystalline (anatase) TiO2 thin films were quantified. Lateral energy transfer from Ru2+* to Os2+ was observed, and the yields were measured as a function of the relative surface coverage and the external solvent environment (CH3CN, THF, CCl4, and hexanes). Excited-state decay of Ru2+*/TiO2 was well described by a parallel first- and second-order kinetic model, whereas OS2+*/TiO2 decayed with first-order kinetics within experimental error. The first-order component was assigned to the radiative and nonradiative decay pathways (tau = 1 mu s for Ru2+*/TiO2 and tau = 50 ns for OS2+*/TiO2). The second-order component was attributed to intermolecular energy transfer followed by triplet-triplet annihilation. An analytical model was derived that allowed determination of the fraction of excited-states that follow the two pathways. The fraction of Ru2+*/TiO2 that decayed through the second-order pathway increased with surface coverage and excitation intensity. Monte Carlo simulations were performed to estimate the RU2+* -> Ru2+ intermolecular energy transfer rate constant of (30 ns)(-1).
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收藏
页码:2598 / 2605
页数:8
相关论文
共 29 条
[21]  
Nozaki K, 1996, NEW J CHEM, V20, P739
[22]   A LOW-COST, HIGH-EFFICIENCY SOLAR-CELL BASED ON DYE-SENSITIZED COLLOIDAL TIO2 FILMS [J].
OREGAN, B ;
GRATZEL, M .
NATURE, 1991, 353 (6346) :737-740
[23]  
PARKER CA, 1960, ANAL LONDON, P587
[24]   Proton-controlled electron injection from molecular excited states to the empty states in nanocrystalline TiO2 [J].
Qu, P ;
Meyer, GJ .
LANGMUIR, 2001, 17 (21) :6720-6728
[25]   Triplet-triplet annihilation of excited states of polypyridyl Ru(II) complexes bound to polystyrene [J].
Shaw, GB ;
Papanikolas, JM .
JOURNAL OF PHYSICAL CHEMISTRY B, 2002, 106 (24) :6156-6162
[26]   Sensitization of nanocrystalline TiO2 initiated by reductive quenching of molecular excited states [J].
Thompson, DW ;
Kelly, CA ;
Farzad, F ;
Meyer, GJ .
LANGMUIR, 1999, 15 (03) :650-653
[27]   Molecular energy transfer across oxide surfaces [J].
Trammell, SA ;
Yang, P ;
Sykora, M ;
Fleming, CN ;
Odobel, F ;
Meyer, TJ .
JOURNAL OF PHYSICAL CHEMISTRY B, 2001, 105 (37) :8895-8904
[28]   Electron injection at dye-sensitized semiconductor electrodes [J].
Watson, DF ;
Meyer, GJ .
ANNUAL REVIEW OF PHYSICAL CHEMISTRY, 2005, 56 :119-156
[29]   ENERGY-TRANSFER AND ELECTRON-TRANSFER SHUTTLING BY A SOLUBLE, BIFUNCTIONAL REDOX POLYMER [J].
YOUNATHAN, JN ;
JONES, WE ;
MEYER, TJ .
JOURNAL OF PHYSICAL CHEMISTRY, 1991, 95 (01) :488-492