OPTICAL SECOND HARMONIC SPECTROSCOPY OF THE ANATASE TiO₂ (101) FACE

Optical Second Harmonic Generation from Periodic Steps on Rutile TiO2(110)

“…For this reason, SHG is sensitive to the surfaces or interfaces of materials with centrosymmetric bulk structures. It has already been applied to the analyses of electronic states on the surfaces and interfaces [7][8][9][10][11][12][13][14]. Maeda et al succeeded in measuring SHG from steps on the Au (887) and (443) single crystal surfaces [9].…”

Selective measurement of the electronic states of the steps on rutile TiO2 (15 15 4) surface by optical second harmonic spectroscopy

“…Note that the spectra shown in Fig. 1 are similar to those of anatase TiO 2 (101) 20. The energy difference between the band gap and the lowest SH peak is 0.7 eV for the anatase TiO 2 (101), while that for the rutile TiO 2 (15 15 4) surface is about 0.6 eV.…”

“…In our previous work,21 we succeeded in detecting the signals of the steps periodically aligned on the TiO 2 surfaces selectively by means of second harmonic generation (SHG)13–20 with nearly normal incident fundamental excitation. We found that both high index TiO 2 (15 15 4) and (671) surfaces with steps have large nonlinear susceptibility elements $\chi_{xxx}^{(2)}$ and $\chi_{xyy}^{(2)}$ , with x representing the [0 0 1] and y representing the [1 1 0] directions.…”