Transient absorption studies of the Ru(dcbpy)2(NCS)2 excited state and the dye cation on nanocrystalline TiO2 film

Ultrafast fluorescence studies of dye sensitized solar cells

“…Much effort has been devoted to this aim in the past 15 years, mainly using nanosecond and femtosecond transient absorption spectroscopy in the visible, near-IR, and mid-IR spectral regions. [2][3][4][5][6][7][8][9][10][11][12] Overall these studies concluded that at least part of the photo-induced electron transfer in the RuN3-TiO 2 films occurs in o100 fs. This was also one of the reasons to believe that the electron injection may occur from non-thermalized vibrationally excited states prior to internal energy relaxation in the sensitizer.…”

Electron injection dynamics in dye-sensitized semiconductor nanocrystalline films

“…Many laboratories have built such transient absorption spectroscopic systems to investigate electron injection process in dye-sensitized semiconductor nanocrystalline films used in DSSCs [9,44,45,64,[74][75][76][77][78][79][80][81]. However, because of often observed complicated reaction kinetics due to inhomogeneous surface nature and overlapping transient absorption bands of intermediate states of the dye (in the excited states and the oxidized state), transient absorption probing in the visible and near-IR region suffers from difficulty in the spectral assignment of the intermediates.…”

A study of electron transfer in Ru(dcbpy)2(NCS)2sensitized nanocrystalline TiO2and SnO2films induced by red-wing excitation

“…3,4 Considerable effort has been devoted to the study of electron injection from the RuN3 dye to TiO 2 , 3,5-12 SnO 2 13,14 and ZnO [15][16][17] films, and electron injection has been found to occur over a wide timescale, from sub-100 fs 4,[7][8][9] to tens of picoseconds. [4][5][6]9,10 A recent study of the electron transfer processes in the RuN3/TiO 2 system shows that the main part (B60%) of the ET occurs from the nonthermalized, initially-excited, singlet state and the rest from the thermalized triplet state when exciting at the absorption maximum of the RuN3 dye at 535 nm. 5,6 The singlet injection channel is characterized by an B50 fs time constant, while triplet injection is much slower, 1-100 ps, and strongly nonexponential.…”